The hardest part of investing is starting. Once you’ve made the first deposit and set up the next one to happen automatically, almost everything else takes care of itself. The math of long-term investing is so favorable that even small, imperfect monthly contributions outperform almost any version of waiting to start.
This is a no-jargon guide to investing for beginners: how to start with as little as $100, what to actually buy, which account to open first, and the two sample portfolios I recommend for $500 and $5,000 starters.
Why most people never start
The three excuses that keep people on the sidelines:
- “I don’t have enough money.” You can open a brokerage account with $0 and buy fractional shares of a $500 stock for $1.
- “I don’t know enough.” The strategy most likely to succeed for the next 40 years is also the simplest: low-cost index funds in tax-advantaged accounts. Read this article and you know enough.
- “It feels risky.” The risk of investing badly is real. The risk of not investing at all is bigger and quieter. Inflation alone steals 2-3% from cash every year.
The fix is to start small and let the habit prove itself. $100 a month at 8% becomes $25,000 in 10 years and $150,000 in 25. The amount matters less than the consistency.
Index funds vs individual stocks
Two roads to choose from at the start.
Individual stocks. Pick specific companies and own their shares directly. Upside: you can outperform the market. Downside: you almost certainly won’t. The S&P SPIVA study consistently finds that 80-90% of professional fund managers fail to beat the market index over 10-year periods. If pros can’t reliably do it, the math against an individual amateur is rough.
Index funds. Own a tiny slice of every company in a given index (the S&P 500, the total US market, the total world market). One purchase gives you diversification across hundreds or thousands of companies. The fund’s return mirrors the index’s return minus a small expense ratio.
The math for the typical investor strongly favors index funds. Vanguard’s VTSAX, Schwab’s SWTSX, Fidelity’s FZROX, and similar total-market index funds charge 0.00-0.04% in fees. Owning them over 30 years means capturing essentially the entire return of the US stock market with negligible cost.
For 95% of beginners, the right answer is to put almost everything into broad index funds and skip stock picking entirely. If you want to scratch the stock-picking itch, allocate 5% to individual stocks as “play money” and accept that this part of your portfolio may underperform.
Roth IRA vs 401(k): which first?
The two main retirement accounts available to most workers.
401(k). Offered by your employer. Higher contribution limit ($23,500 in 2025). Often includes an employer match. Traditional 401(k) contributions are pre-tax (lower your taxable income now, pay tax in retirement). Roth 401(k) contributions are after-tax (no current deduction, tax-free in retirement).
Roth IRA. Open it yourself at any brokerage. Lower contribution limit ($7,000 in 2025). After-tax contributions, tax-free growth, tax-free withdrawals in retirement. Income limits apply ($165,000 single, $246,000 married in 2025).
The standard sequence:
- Contribute enough to your 401(k) to capture the full employer match. This is free money. Skipping it leaves money on the table.
- Max out your Roth IRA. Tax-free growth for 30-40 years is incredibly valuable, especially early in your career when your tax rate is low.
- Go back to the 401(k) and contribute more. Eventually max it ($23,500/year).
- HSA if you have one available. Triple tax advantage when used for medical expenses.
- Taxable brokerage once tax-advantaged accounts are maxed.
The reasoning behind Roth IRA before more 401(k): tax-free growth becomes more valuable the longer the horizon. For someone in their 20s or 30s, the Roth’s tax-free decades of growth typically wins. As you approach retirement, the traditional 401(k)’s current tax deduction becomes more attractive.
Use our Compound Interest Calculator to model what consistent contributions in either account look like over 30 years.
Dollar-cost averaging: a 10-year example
Dollar-cost averaging (DCA) means buying a fixed dollar amount on a regular schedule, regardless of price. When prices are high, you buy fewer shares. When prices are low, you buy more. Over time, the average cost per share comes out lower than if you tried to time the market.
A realistic example. Imagine investing $500/month in a total stock market index fund from 2015 to 2024. The fund’s price varied widely – up in some months, down in others. By the end of 2024, the $60,000 in total contributions grew to roughly $115,000-130,000 depending on entry points, an 80-100% gain over the 10-year period.
The interesting part isn’t the total. It’s that the result is approximately the same whether you started during a “good time” or a “bad time.” DCA smooths out timing risk. The investor who started in March 2020 (right at the COVID crash) made more on a per-month basis than the investor who started in early 2021 (right before a correction) – but both came out ahead of their starting amounts.
The takeaway: pick a monthly amount, set it to fire automatically the day after payday, and stop trying to time the market. The “right time” to start is whenever you can.
How to pick a brokerage account
The major retail brokerages are now functionally identical for index fund investing.
Vanguard. The original low-cost index fund pioneer. Best for buy-and-hold investors. Interface is functional, not flashy.
Fidelity. Zero-fee index funds (FZROX, FZILX). Excellent customer service. Strong for retirement accounts.
Charles Schwab. Strong all-around. Good for combining brokerage and banking.
Robinhood, Webull, Cash App Investing. Built for active trading. Less suited for retirement-focused investing. Not recommended as your primary account.
Pick one of the first three. Open an account. The application takes 10-15 minutes. Initial deposit can be $0; most allow $1 to start buying fractional shares.
A $500 starter portfolio
For someone starting with $500 (one-time) plus $50-100/month going forward, the simplest sound portfolio is one fund.
- 100% in a total US stock market index fund (VTI, VTSAX, FZROX, or SWTSX). One purchase, total diversification, expense ratio under 0.05%.
That’s the entire portfolio. You don’t need bonds at this stage if you’re under 40 and won’t touch the money for 10+ years. Add an international index fund (VXUS, FZILX) when the portfolio reaches $5,000 and you want to diversify beyond US stocks.
A $5,000 starter portfolio
At $5,000, a slightly more diversified portfolio:
- 70% US total stock market (VTI/VTSAX/FZROX)
- 20% International stocks (VXUS/FZILX)
- 10% Bonds (BND/FXNAX) – only if you want to dampen volatility, otherwise stay 80/20 stocks
Or, the even simpler one-fund solution: a target-date retirement fund (Vanguard Target Retirement 2065, Fidelity Freedom Index 2065). Pick your approximate retirement year, buy one fund, and the fund handles all rebalancing automatically. Expense ratios run 0.08-0.15%.
For 90% of investors, a target-date fund or a three-fund portfolio (US, International, Bonds) is the right long-term portfolio.
What about crypto, real estate, private companies?
Three “alternative” categories that come up constantly.
Crypto. High volatility. No earnings or yield underlying the price. Speculative. If you want exposure, allocate 1-5% of your portfolio and accept that it may go to zero.
Real estate. Through REITs (real estate investment trusts), you can get real estate exposure inside a regular brokerage account. Direct rental property investing is a part-time job, not a passive investment.
Private companies / startups. Most require accredited investor status (high net worth or income). Returns are concentrated in a few winners; most lose money. Not appropriate as a core holding.
The boring index fund portfolio outperforms most exotic alternatives over long time horizons. Stick with boring.
Common beginner mistakes
A few traps that catch new investors:
- Trying to time the market. Almost nobody beats DCA over the long term.
- Panic selling during downturns. The worst returns belong to investors who sell when markets drop. The best returns belong to those who keep buying.
- Chasing recent winners. Last year’s best stock or fund is rarely next year’s. Stick with diversification.
- Paying high expense ratios. A 1% expense ratio sounds small but costs you 25-30% of your portfolio over 40 years.
- Forgetting tax shelter. Use tax-advantaged accounts first. Taxable accounts last.
Key takeaways
- Start now, even with $100. The habit matters more than the amount.
- Index funds beat stock picking for almost all investors over long horizons.
- Sequence: 401(k) match → Roth IRA → max 401(k) → HSA → taxable.
- Dollar-cost averaging beats market timing.
- One total-market fund is enough at $500. Three funds or a target-date fund is enough at $5,000.
- Skip exotic investments until your core portfolio is built.
Frequently Asked Questions
Can I start investing with $100? Yes. Open a brokerage account, deposit $100, and buy fractional shares of a total market index fund. Set up $50-100/month auto-contributions afterward.
What return should I expect? The US stock market has averaged about 10% annually over the long term (7% after inflation). Future returns may be lower. For planning, 7% real is a defensible assumption.
Should I invest if I have debt? At minimum, contribute enough to get the full 401(k) match while paying down debt. For high-interest debt above 7-8%, prioritize debt payoff over additional investing. For low-interest debt, invest concurrently.
How often should I check my portfolio? Quarterly is plenty. Daily checking causes stress-driven decisions during normal volatility.
Should I sell during a market crash? No. Selling locks in losses. The best long-term returns belong to investors who keep buying through downturns. If you can’t handle the volatility emotionally, shift to a more conservative allocation – but don’t sell out of the market entirely.