Choosing an ETF means choosing holdings, a way to receive returns and a path through market declines. Start with broad-market exposure or a focus on particular companies and industries. That choice points to the comparison to read next.

Which choice are you trying to make?

Owning a broad US market portfolio differs from focusing on growth companies or semiconductors. If you have no fund in mind yet, start with one of the questions below.

For dividends you plan to spend, explore income planning. For daily 2x or 3x products, start with the guide to their structure and risk.

Whole market or large companies: VTI vs VOO Growth exposure: SPY vs QQQ Costs for the same index: QQQM vs QQQ A focus on semiconductors: SOXX vs SMH Dividends for spending: income planning Daily 2x or 3x: structure and risk

Equal contributions, different balances and declines: SPY vs QQQ

S&P 500 vs Nasdaq-100 · 2021-09-22 → 2026-09-22

Initial contribution: 1000 USD; monthly contribution: 500 USD. Dividends reinvested. Total contributions: $31,500.00.

USD, without currency conversion. Personal taxes and trading fees excluded.

Price data through 2026-09-22
MeasureQQQSPY
Final value$57,861.38$50,467.16
Return on contributions+83.69%+60.21%
MDD−35.12%−24.51%

The two funds received the same contributions. Their ending balances and declines differed. A larger ending balance leaves the holding experience to examine. The full study connects these results to the companies and sectors each fund owns.

How to read these returns and drawdowns

Monthly contributions are scheduled on day 1. Returns use contributed capital, not a lump-sum annual rate. The cash-flow annual rate is XIRR. MDD follows the performance series adjusted for new contributions. Inflation is excluded. This is one observed period, not a forecast.

Read the full study and calculation conditions

Do two ETFs give you twice the diversification?

One ETF can hold many businesses. The number of funds and the degree of diversification are different measures. Two funds with large weights in the same companies can overlap more than you expect.

The VTI and VOO study looks beyond the number of stocks to their actual weights. Ask how much owning more companies changes your portfolio. Diversification still leaves you exposed to market losses.

Why can ETFs feel different to hold?

SPY and QQQ track different indexes, with different company and sector weights. Semiconductor funds also differ in the weights they assign to individual businesses within the industry.

I think the businesses and strategy behind a return deserve attention before the return itself. Once you find an area of interest, read its comparison for both the holdings and the declines investors experienced.

Two checks beyond returns: drawdowns and costs

An attractive final balance still leaves the declines along the way to examine. MDD is the largest fall from a previous peak. Ending value and maximum drawdown answer different questions, even with identical contributions.

For funds tracking the same index, compare expenses, trading volume and bid-ask spreads. The QQQM and QQQ study examines costs and trading convenience when holdings are similar.

Have a candidate? Change the dates and contribution pattern

A result from one period can hide the effect of the starting date. Read the SPY and QQQ ten-year studies, or change the backtest dates to examine a different decline.

Match lump-sum or monthly contributions as well. New money added to an account is not all investment gain. Match dates, amounts, currency and dividend treatment, then check whether taxes, trading costs and FX conversion are included.

Compare your ETF candidates under matching conditions

Understand the holdings and strategy first, then explore fund comparisons and contribution patterns.

Research using actual historical data

Continue with VTI and VOO for market breadth, SPY and QQQ for growth exposure, or QQQM and QQQ for costs within the same index. Use the specialist guides above for income and leverage.

ETF comparisons

SOXX vs SMH Backtest: 10-Year Returns, MDD and Volatility

A semiconductor ETF offers a way to participate in several businesses together. I believe studying the industry, holdings and backtests should go hand in hand. Follow KRW 100 million invested separately in SOXX and SMH over ten years through growth, declines and recovery.

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More research in this topic

Frequently asked questions

How does trading an ETF differ from trading a mutual fund?

An ETF trades on an exchange during the day at market prices. A typical non-listed mutual fund trades at net asset value determined at a specified valuation time. An ETF’s market price can also differ from its net asset value.

Why are there several ETFs tracking the same index?

Issuers, fees and trading volume can differ. Tracking the same index does not make execution costs or trading convenience identical. The QQQM and QQQ study explores these differences.

Should I subtract fund expenses again from a reported return?

If the performance already reflects fund expenses, subtracting the same expense again counts it twice. Personal taxes and trading fees need a separate check.

Concept sources · checked October 9, 2026

These guides support understanding and comparison. Historical performance and assumed rates do not guarantee future results. Calculations can exclude taxes and trading costs; check the conditions on each page.

Calculation methods and limitations · Compare two ETF candidates