How to Start Investing With $100: A Beginner’s Guide

Last updated: September 2, 2026

Yes, $100 may be enough to begin investing. Some brokerage accounts carry no minimum opening deposit, and fractional-share programs allow purchases smaller than one full share. But whether that particular $100 should be invested depends on when you may need the money, your current cash reserves, any debt costs you carry, and your tolerance for investment losses. The amount is small enough that fees and account minimums matter significantly. A single $100 investment will not generate meaningful income or wealth on its own. If additional contributions are made over time, their cumulative effect can become much larger than the first $100.

Key Takeaways

• Some brokerage accounts accept $100 or less to open, but not all investment products are accessible at that amount.
• Fractional shares allow you to buy less than one full share of a stock or ETF, but owning a fraction of one company does not create diversification.
• A one-time $100 investment at a hypothetical 7% annual return grows to approximately $197 in 10 years, $387 in 20 years, and $761 in 30 years, before taxes, fees, and inflation.
• In the article’s hypothetical example, adding $100 per month for 10 years has a much larger effect than the original $100 deposit.
• Fixed platform fees (such as a $1 per month subscription) represent 12% of a $100 balance annually, a ratio that shrinks as the account grows.
• “Possible” and “appropriate” are different questions. Near-term cash needs, emergency reserves, debt costs, and investment time horizon can all affect the decision.
• Savings accounts, CDs, and Treasury securities are not the same as stock-market investments; they serve different purposes and carry different risks.
• SIPC protects against missing assets at a failed brokerage; it does not protect against ordinary market losses.

Introduction

A single $100 bill raises a practical question: can it actually be invested, and if so, should it be? Some brokerage firms and fractional-share programs make it technically possible to invest with $100 or less, although availability, minimums, and eligible securities vary. The mechanics are accessible. The harder questions are financial: Is this money needed soon? Is there higher-priority debt? What does $100 realistically accomplish inside an investment account?

This guide answers those questions directly. It covers account types, what $100 can purchase, how fees affect small balances, what the math looks like with and without ongoing contributions, and how to think through the decision before depositing anything. It does not tell every reader to invest immediately, because that depends on individual circumstances this article cannot assess.

Can You Really Start Investing With $100?

Yes, depending on the account type, brokerage, investment product, and minimum purchase requirements, but the answer is not uniform across all platforms or products.

Some brokerage accounts can be opened with little or no initial deposit, while others have account or product minimums. Some firms also allow fractional-share purchases, meaning an investor can buy less than one full share. This makes certain investments accessible at $100 or less. However, not every broker offers fractional shares, and not every security is available fractionally even at brokers that support the feature. Fractional-share programs vary by firm. The SEC and FINRA note that eligible securities, order handling, voting rights, and transferability can differ; fractional shares often cannot be transferred in-kind to another brokerage. See Investor.gov’s fractional-share bulletin and FINRA’s fractional-share guide.

Mutual funds are a different case. Many traditional mutual funds still require minimum initial investments that exceed $100, sometimes substantially. ETFs (exchange-traded funds) trade like stocks on an exchange and can be purchased by the share or fractionally where supported, but the per-share price and fractional availability depend on the broker and the specific fund.

Fees deserve attention at this balance level. A $100 account is small enough that even modest fixed fees, a monthly subscription, an account maintenance charge, or a per-trade commission, can represent a meaningful percentage of the balance. That ratio matters and is covered in detail later in this article.

For a broader foundation on investing as a beginner, see the complete beginner investing guide on The Rich Guy Math.

Before Investing the $100, Ask What the Money Is For

Not every $100 belongs in an investment account. The right place for money depends on what that money needs to do and when.

Short-term money is money needed within the next few months: rent, a bill, a known expense. Putting short-term money into a market investment creates a timing problem: if the market falls before you need the funds, you may be forced to sell at a loss.

Emergency money is money intended for unexpected expenses or income disruptions. The appropriate reserve differs by household. The CFPB notes that emergency savings can help reduce reliance on credit or loans when a financial shock occurs. Because emergency funds are meant to be available when needed, liquidity and stability matter. See the CFPB emergency-fund guide.

Long-term investment money generally has a longer time horizon and can tolerate more uncertainty in value than money assigned to an upcoming bill or emergency need.

Debt is also part of the calculation. Paying down a debt provides a known, certain reduction in borrowing cost. Investment returns are uncertain. If the interest rate on a debt is high, the comparison between paying it down and investing deserves careful thought. Employer retirement-plan contributions may also affect the comparison because plan-specific matching or nonelective contributions change the economics.

This article cannot tell any individual reader what to do with their $100. It can only describe the trade-offs.

The Rich Guy Math: What Can $100 Actually Become?

This section shows what a single one-time $100 investment could hypothetically become over time, with no additional contributions.

Assumptions:

• Starting amount: $100
• Hypothetical annual return: 7% (this is not a forecast or expected return)
• Compounding: annual
• No taxes, no fees, no inflation adjustment, no volatility
• This is a mathematical illustration only

Formula: Future Value = Present Value × (1 + r)^n

Hypothetical illustration only. Not a market forecast. Actual investment results will differ and may include losses.

The numbers are modest. $100 invested once, left untouched for 30 years at this hypothetical rate, becomes roughly $761. That is meaningful growth in percentage terms, but the dollar amount remains limited because the starting base is small. This is why the initial $100 matters less than what comes after it.

To explore these calculations further, use the compound interest calculator on The Rich Guy Math.

The Bigger Math: $100 Plus Regular Contributions

The more instructive calculation includes ongoing contributions alongside the initial $100.

Assumptions:

• Starting amount: $100
• Regular contribution: $100 at the end of each month
• Hypothetical annual return: 7%
• Compounding: monthly
• Time: 10 years
• No taxes, no fees, no inflation adjustment
• This is a mathematical illustration only

Using the future value of an annuity formula:

FV = P × [((1 + r/n)^(n×t) − 1) / (r/n)] + PV × (1 + r/n)^(n×t)

Where: P = $100/month, r = 0.07, n = 12, t = 10, PV = $100

• Future value of the initial $100: $100 × (1 + 0.07/12)^120 ≈ $201
• Future value of monthly contributions: $100 × [((1.005833)^120 − 1) / 0.005833] ≈ $100 × 173.08 ≈ $17,308
• Combined hypothetical total: approximately $17,509

Separating contributions from hypothetical growth:

Hypothetical illustration only. Not a market forecast. Actual results will differ and may include losses.

In this hypothetical, the initial $100 grows to about $201, while the repeated $100 monthly contributions account for most of the ending value. The point is not that monthly investing guarantees a result; it is that repeated contributions can have a much larger cumulative effect than one small deposit.

Should I Invest $100 or Pay Off Debt First?

Debt repayment and investing involve different trade-offs, so the comparison should start with the actual borrowing cost, liquidity needs, account benefits, and uncertainty of investment returns.

Debt repayment provides a known, certain benefit: reducing a balance at a stated interest rate eliminates that interest cost with certainty. Investment returns are not certain. A market investment might return more than the debt’s interest rate, less, or it could lose value.

Factors to consider:

• What is the interest rate on the debt?
• Is the debt rate fixed or variable?
• Does an employer offer retirement-plan matching contributions? If so, the match changes the effective return on those contributions.
• Is the debt secured (such as a mortgage) or unsecured (such as a credit card)?
• What is the tax treatment of the debt interest?

There is no universal interest-rate threshold that settles the decision for every household. The comparison involves certainty (debt payoff) versus uncertainty (investment returns), and individual circumstances vary.

Step 1: Choose the Type of Account

The account and the investment are separate decisions. An account determines tax and access rules; the investment determines what assets you actually own.

Taxable brokerage account

A taxable brokerage account does not have the same retirement-specific contribution limits or age-based distribution rules as an IRA. Investment income, dividends, and realized gains may create tax consequences depending on the transaction and the investor’s circumstances. Brokerage settlement, transfer, and withdrawal procedures still apply.

Traditional IRA

A Traditional IRA is a retirement account. Contributions may be deductible depending on income and workplace-plan coverage. Taxable distributions are generally included in income, and distributions before age 59½ may be subject to an additional 10% tax unless an exception applies. See the IRS IRA withdrawal guidance.

Roth IRA

Roth IRA contributions are made with after-tax dollars. Qualified distributions can be tax-free, while nonqualified distributions can have different tax treatment. Income limits and contribution rules apply. See the IRS Traditional and Roth IRA overview.

Workplace retirement plan

A 401(k), 403(b), or similar workplace plan is offered through an employer and follows the plan’s own investment menu, contribution rules, fees, and employer-contribution terms.

No account is universally best for a $100 starting amount. Account choice can depend on earned income, tax situation, employer benefits, time horizon, withdrawal needs, and fees.

Step 2: Understand What You Can Buy With $100

$100 can reach different investment products depending on the broker and the product’s minimums.

Fractional shares
Ownership of less than one full share of a stock or ETF. Available at some brokers for some securities. Allows participation in higher-priced securities at a smaller dollar amount. Transfer rules vary by broker; fractional positions may not transfer in-kind.

ETFs (exchange-traded funds)
Funds that trade on an exchange like individual stocks. Can be purchased by the share or fractionally where supported. Expense ratios (annual fund costs) vary. Not all ETFs are diversified; the holdings determine that, not the structure.

Mutual funds
Pooled investment funds priced once per day after market close. Many traditional mutual funds have minimum initial investment requirements that exceed $100. Some fund families have reduced or eliminated minimums; verify directly with the fund or broker.

Individual stocks
Shares of a single company. Available at most brokers; fractional shares available at some. Concentrates exposure in one company.

Treasury securities
Debt issued by the U.S. federal government. Marketable Treasury bills, notes, bonds, TIPS, and floating-rate notes can be purchased through TreasuryDirect or through certain financial institutions. TreasuryDirect states that marketable Treasury securities have a $100 minimum purchase and $100 increments. They are not FDIC-insured bank deposits. See TreasuryDirect’s marketable-securities FAQ.

Cash and deposit products
Savings accounts and certificates of deposit (CDs) at banks are not investment products in the market sense. They are covered separately below.

Fractional Shares: Useful, But Not Diversification by Themselves

A fractional share means owning less than one full share of a stock or ETF. This is a useful feature for accessing higher-priced securities with a small dollar amount, but it is frequently misunderstood as a diversification tool.

Owning a fraction of one company is still owning one company.

If $100 is used to buy a fractional share of a single corporation, the entire $100 is exposed to that one company’s performance. The fact that the position is fractional does not change the concentration. A company-specific event- an earnings miss, a regulatory action, a product failure- affects the entire position.

Diversification comes from the underlying holdings, not from the fractional structure.

If $100 is used to buy a fractional share of a broadly diversified fund that holds hundreds or thousands of underlying securities, the $100 has exposure to those many holdings. The diversification exists because the fund holds many positions, not because the share is fractional.

This distinction matters when evaluating what $100 actually owns. Before purchasing a fund, review its underlying holdings, strategy, and concentration. For a deeper comparison, see ETFs vs. Individual Stocks.

ETFs vs. Individual Stocks With $100

An individual stock represents one company. The entire investment is exposed to that company’s specific risks, management decisions, competitive position, financial health, and sector conditions.

A diversified ETF may hold many companies within a single fund structure, which reduces company-specific concentration. If one holding performs poorly, it is one of many. However, not every ETF is diversified. A sector ETF concentrating on one industry, or a single-stock ETF, carries different risk characteristics than a broad-market fund. The fund’s holdings determine its diversification, not its label.

Neither structure eliminates investment risk. Both can lose value.

This article does not recommend specific funds or tickers. For a full comparison of these two structures, see ETFs vs. Individual Stocks.

What About Index Funds?

“Index fund” describes an investment strategy, not one legal structure. An index fund can be structured as an ETF or as a mutual fund.

• Index ETF: trades on an exchange during the trading day. It may be available fractionally depending on the brokerage.
• Index mutual fund: priced once per day after market close and may have a minimum initial investment.

An ETF is not automatically an index fund, and an index fund is not automatically an ETF. Before buying any fund, check the index or strategy it follows, its holdings, expense ratio, purchase minimums, and other fees.

What About Index Funds?

“Index fund” describes an investment strategy, not a single legal structure. An index fund tracks a market index, a defined list of securities, rather than selecting holdings through active management.

An index fund can be structured as:

• An ETF, traded on an exchange throughout the day
• A mutual fund, priced once daily after market close

These are not interchangeable terms. An ETF is not automatically an index fund, and an index fund is not automatically an ETF. Some index mutual funds carry minimum initial investment requirements. Some index ETFs can be purchased fractionally depending on the broker. Costs and holdings vary across both structures.

Before buying any fund labeled as an index fund, check: What index does it track? What does that index contain? What is the expense ratio? What are the purchase minimums at the broker you are using?

Should You Use a Robo-Advisor?

A robo-adviser is an automated digital investment advisory program. The SEC notes that these services typically collect information about goals, time horizon, income, assets, and risk tolerance and then use that information to create and manage a portfolio. Services and fees vary widely. See Investor.gov’s robo-adviser bulletin.

Robo-advisers generally handle:

• Portfolio construction from a menu of funds
• Periodic rebalancing to maintain target allocations
• In some cases, tax-loss harvesting

They charge fees, either a percentage of assets under management, a flat subscription fee, or both. The underlying funds also carry their own expense ratios. On a $100 balance, even a small percentage fee or a fixed monthly charge can represent a significant portion of the account value.

Some robo-advisers have no minimum balance requirement. Others require $500 or more to start. Verify minimums and fee structures directly with any platform before opening an account.

A robo-adviser does not eliminate investment risk. Portfolios can lose value. The automation handles implementation, not outcomes.

What About Micro-Investing Apps?

Micro-investing apps are platforms designed for very small, frequent investments. Common features include:

• Round-up investing (rounding purchases to the nearest dollar and investing the difference)
• Small recurring deposits on a schedule
• Fractional share purchases
• Automated portfolio management

These features can make it easier to invest small amounts on a schedule, but the service model and fees vary by platform.

The fee math matters here specifically.

Some small-account investing or advisory services charge fixed subscription fees. The SEC specifically warns that subscription-based advisory fees can represent a large percentage of a small account. See Investor.gov’s subscription-fee bulletin.

Rich Guy Math callout:

A $3 monthly subscription on a $100 account equals $36 per year. That is 36% of the starting balance consumed by the subscription fee alone, before any investment gain or loss. This does not mean the investment itself carries a 36% expense ratio. It illustrates how a fixed fee becomes proportionally large when the account balance is small.

As the account grows through contributions and hypothetical returns, that same $36 annual fee becomes a smaller percentage. The problem is most acute at the beginning, when the balance is lowest.

The Rich Guy Math: Why Fees Matter More on Small Balances

Fixed fees behave differently than percentage-based fees. A percentage fee scales with the account; it takes the same share regardless of balance size. A fixed fee takes a larger share from a smaller account.

Illustration:

Simple ratio illustration. Actual account balances change over time. Platforms use different pricing structures. This table does not represent any specific platform.

The same $12 annual fee (equivalent to $1 per month) represents 12% of a $100 account but only 0.12% of a $10,000 account. This is not a criticism of any specific platform; it is a mathematical property of fixed fees applied to variable balances.

When evaluating any platform for a $100 starting investment, calculate the annual fee as a percentage of the expected balance. If that percentage is high, compare alternatives before committing.

Savings, CDs, and Treasury Securities Are Not the Same as Stock Investing

These products are sometimes grouped as “safer options,” but they serve different purposes and carry different characteristics. Treating them as interchangeable leads to confusion.

Savings accounts
Bank deposit products. Eligible deposits at FDIC-insured banks are covered under FDIC rules, generally up to $250,000 per depositor, per insured bank, per ownership category. Rates can change. See the FDIC deposit-insurance FAQ.

Certificates of deposit (CDs)
Bank time-deposit products. Terms, rates, and early-withdrawal provisions vary by institution and product. Eligible CDs at FDIC-insured banks can receive deposit-insurance coverage under FDIC rules.

Treasury securities
Debt obligations of the U.S. federal government. Marketable Treasuries can be bought through TreasuryDirect or certain financial institutions. They are not FDIC-insured deposits, although Treasury obligations are backed by the full faith and credit of the U.S. government. Market price, inflation exposure, liquidity, and interest-rate sensitivity depend on the security and whether it is held to maturity or sold earlier.

Stocks and ETFs
Market investments. Value fluctuates based on market conditions. Not FDIC-insured. Not government-guaranteed. Can lose value, including the full amount invested.

These four categories solve different problems. These categories solve different problems. Deposit products emphasize liquidity and principal stability under their terms; Treasury securities have government backing but are not bank deposits; stocks and stock funds accept market-price risk in pursuit of investment returns. The relevant comparison depends on what the money needs to do and when.

Does $100 Belong in an Investment or in Savings?

This framework is educational rather than personalized advice.

The table does not produce an automatic answer. It identifies the variables that should be understood before the $100 is committed.

How to Evaluate a Brokerage Before Depositing $100

Publishing a “best broker” list is less useful than explaining what to compare. Brokerage features change, and the right fit depends on what the investor needs.

Factors to compare:

• Account minimum: Does the broker require a minimum deposit to open or maintain an account?
• Fractional shares: Are they available? For which securities? What are the minimum purchase amounts?
• Investment choices: Does the broker offer the account type (taxable, IRA) and investment products (ETFs, mutual funds, individual stocks) you need?
• Fund minimums: If you plan to buy mutual funds, what minimums apply?
• Commissions: Are stock and ETF trades commission-free? Are there per-trade fees for other products?
• Subscription or account fees: Are there monthly or annual platform fees? Calculate these as a percentage of your expected balance.
• Automatic investing: Can you set up recurring contributions?
• Customer service: What support channels are available?
• SIPC membership: Is the broker a SIPC member?
• Transfer policies: How are fractional shares handled if you transfer accounts?
• Cash sweep: Where does uninvested cash go, and what does it earn?

A note on SIPC: SIPC works to restore missing cash and securities when a SIPC-member brokerage fails. The statutory protection limit is $500,000 per customer, including up to $250,000 for cash. SIPC does not protect against market losses or guarantee investment performance. See SIPC’s official protection guide.

A Simple $100 Investing Decision Tree

Use this only as an educational checklist:

1. Could the money be needed soon?
If yes, compare options that prioritize liquidity and principal stability before accepting market-price risk.

2. Would losing part of the $100 create a problem?
If yes, that is an important constraint on how much investment risk the money can reasonably absorb.

3. Do you understand what you would own?
One company means company-specific concentration. A diversified fund may spread exposure across many holdings, but not every fund is broadly diversified.

4. Have you checked the fees?
With a $100 balance, a fixed monthly or annual charge can represent a large percentage of the account.

5. Does the account type fit the goal?
A taxable brokerage account and a retirement account have different tax and access rules.

This decision tree identifies questions; it does not tell an individual reader what to buy.

What Fees Should I Watch Out For With Small Investments?

Fixed fees can be especially significant on a $100 balance because the same dollar fee represents a larger percentage of a smaller account. A $1 monthly fee is trivial on a $10,000 account but equals 12% of a $100 account annually.

Fee types to check before opening any account:

• Monthly or annual platform subscription fees
• Account maintenance fees
• Per-trade commissions (common on options; less common on stocks/ETFs at major brokers)
• Fund expense ratios (the annual cost built into the fund itself, expressed as a percentage)
• Transfer-out fees if you want to move the account later
• Inactivity fees

Expense ratios on funds are percentage-based, so they scale with the balance. A 0.05% expense ratio on a $100 balance corresponds to $0.05 over a year if the balance stayed at exactly $100; actual fund expenses are deducted from fund assets and account values change. The same ratio on $100,000 costs $50. Percentage-based fees are less distorting on small balances than fixed fees.

The SEC recommends reviewing account documents, fee schedules, prospectuses, and other disclosures to understand both transaction and ongoing fees. See Investor.gov’s 2025 fee bulletin.

What Happens If a $100 Investment Falls?

Market investments can decline in value. An individual stock can, in an extreme case, become nearly worthless. A diversified fund can also experience substantial losses even though the chance of every underlying holding simultaneously becoming worthless is a different risk.

If a $100 position falls to $60:

$100 − $60 = $40 loss

$40 ÷ $100 = 40% decline

Recovering from $60 back to $100 would then require a gain of:

$40 ÷ $60 = 66.7%

That recovery math is one reason risk matters even when the starting dollar amount is small.

SIPC does not reimburse ordinary market losses, and FDIC deposit insurance does not cover stocks, bonds, ETFs, or mutual funds. The protections apply to different risks.

Lump Sum vs. Regular Contributions: Two Different Decisions

Two situations are often confused.

Situation 1: The full amount is already available.
A person has investable cash today and is deciding whether to invest it immediately or deliberately hold part of it in cash and phase it into the market.

Vanguard’s 2023 research compared those approaches across historical and simulated data and found that immediate lump-sum investing outperformed a common cost-averaging strategy roughly two-thirds of the time in the periods studied. That finding is historical research, not a guarantee about the next market period. See Vanguard’s cost-averaging research.

Situation 2: New money arrives from future income.
Someone has $100 today and expects to contribute more from future paychecks. In that case, future monthly contributions are not the same as intentionally keeping today’s investable cash out of the market.

Regular contributions can simplify implementation, but neither immediate investing nor periodic investing guarantees a profit.

Common Mistakes When Starting With $100

Treating $100 like a lottery ticket. Concentrating a small balance in high-risk, speculative positions in hopes of a large gain amplifies the probability of loss.

Buying something because its share price looks cheap. A low share price does not indicate value. A $2 stock is not “cheaper” than a $200 stock in any meaningful sense; the share price alone says nothing about the company’s valuation or prospects.

Confusing fractional shares with diversification. Owning a fraction of one company is still owning one company. Diversification depends on what the investment holds, not on whether the position is fractional.

Ignoring fees. A fixed monthly fee on a $100 account can consume a significant percentage of the balance annually. Calculate fees before choosing a platform.

Buying an ETF without checking its holdings. Not every ETF is broadly diversified. Some track narrow sectors, specific themes, or use leverage. The holdings determine the risk profile.

Choosing a brokerage only because of an advertisement. Marketing materials are not a substitute for reviewing fee schedules, investment options, and account terms.

Using money needed soon. Market volatility can be a poor match for money that must be available at a specific near-term date.

Chasing recent performance. An investment that performed well recently may not continue to do so. Past performance does not predict future results.

Assuming a high dividend yield means high return. A high yield can reflect a falling share price or an unsustainable payout. Total return includes both price change and income.

Trading frequently because the dollar amount feels small. Frequent trading can create taxes, spreads, commissions, or other costs depending on the account and product, and it increases the number of decisions the investor must get right.

What $100 Cannot Do

This section is not discouraging; it is accurate.

• $100 alone is unlikely to generate substantial investment income; the dollar amount limits how much cash income a modest yield can produce.
• It will not create instant diversification if placed into a single company or narrow fund.
• It cannot eliminate investment risk. All market investments carry the possibility of loss.
• It cannot guarantee any particular outcome or rate of return.
• It cannot compensate for high recurring platform fees indefinitely on a small balance.
• It cannot replace a sustained savings and investment process. One $100 deposit is a starting point, not a financial plan.

What $100 Can Do

• Help a beginner learn how brokerage accounts work: opening, funding, placing an order, reading a statement.
• Allow a small first investment where account and product minimums are met.
• Provide a small-dollar way to observe how account values, prices, fees, and statements work in practice.
• Create a starting point for future contributions, if additional contributions fit the investor’s plan.
• Help someone learn about fees, diversification, and risk through direct experience with a manageable amount.

Is Investing $100 Worth It?

From a purely dollar-return perspective, a single $100 investment has limited financial impact. The hypothetical math shows this clearly: even at a fixed 7% annual return over 30 years, $100 becomes approximately $761. That is real growth in percentage terms, but a modest dollar amount.

From an educational and habit-building perspective, starting with a manageable amount may help someone learn the mechanics of investing, account types, order placement, fee structures, and the experience of holding an investment through price changes. Those lessons have value that extends beyond the $100 itself.

The financial value of investing $100 becomes more meaningful if additional contributions follow, but those returns remain uncertain, and the decision to invest at all depends on individual financial circumstances that this article cannot assess.

The answer is not “yes, always.” It is: it depends on what the money is for, what comes after it, and what the investor understands before they start.

Conclusion

How to start investing with $100 is a practical question with a practical answer: it is technically possible at many brokers, but whether it is the right move depends on the financial context around that $100.

The math is clear. A one-time $100 investment grows modestly. Regular contributions grow substantially more. Fees matter disproportionately on small balances. Fractional shares are useful but not a diversification shortcut. Account type affects taxes and access. And “possible” is not the same as “appropriate.”

Actionable next steps for a beginner considering this decision:

1. Determine whether the $100 is short-term money, emergency money, or genuinely available for long-term investment.
2. If debt exists, compare its borrowing cost with the uncertainty and liquidity trade-offs of investing.
3. Review account types (taxable brokerage, IRA) and their tax treatment at IRS.gov.
4. Research brokerage platforms by comparing account minimums, fractional-share availability, and fee structures, not by advertisement.
5. Before buying any fund or stock, check what it actually holds.
6. Calculate any fixed platform fees as a percentage of the expected account balance.
7. Read about investment risk at Investor.gov before placing a first order.
8. If additional contributions are planned, decide how they fit the budget and account rules.

For the complete beginner investing roadmap beyond the $100 question, see How to Start Investing as a Beginner on The Rich Guy Math.

Sources and References

• Investor.gov — Fractional Share Investing
• FINRA — Investing in Fractional Shares
• Investor.gov — Robo-Advisers
• Investor.gov — Subscription-Based Advisory Fees
• Investor.gov — How Fees and Expenses Affect Your Investment Portfolio
• CFPB — An Essential Guide to Building an Emergency Fund
• FDIC — Deposit Insurance FAQs
• TreasuryDirect — Marketable Securities FAQs
• SIPC — What SIPC Protects
• IRS — Traditional and Roth IRAs
• IRS — IRA Distributions and Withdrawals FAQs
• Vanguard Research — Cost Averaging: Invest Now or Temporarily Hold Your Cash?

Editorial Disclosure

The Rich Guy Math provides general financial education and calculation tools. We may discuss financial products, investments, accounts, or services for educational and illustrative purposes, but we do not provide individualized financial, investment, tax, legal, or accounting advice. Investing involves risk, including possible loss of principal.

About the Author

Max Fonji is the founder and financial education writer behind The Rich Guy Math. He researches and explains personal-finance concepts using calculations, authoritative sources, practical examples, and plain language. His work focuses on helping readers understand how money decisions work rather than providing individualized financial advice.