If you invested $100 a month in Costco
Buying $100 at each monthly close from November 2016 through October 2026, with dividends reinvested, turns $12,000.00 contributed into $36,884.69 as of October 23, 2026. Annualized money-weighted IRR: 21.57%.
| Monthly schedule | Invested | Value | Annualized (money-weighted IRR) | SPY same-schedule value (reinvested) |
|---|---|---|---|---|
| 5 years · $50/month | $3,000.00 | $4,497.72 | 16.72% | $4,602.42 · 60 contributions · $3,000.00 invested · 2021-10 to 2026-10 |
| 5 years · $100/month | $6,000.00 | $8,995.45 | 16.72% | $9,204.83 · 60 contributions · $6,000.00 invested · 2021-10 to 2026-10 |
| 5 years · $500/month | $30,000.00 | $44,977.24 | 16.72% | $46,024.17 · 60 contributions · $30,000.00 invested · 2021-10 to 2026-10 |
| 10 years · $50/month | $6,000.00 | $18,442.35 | 21.57% | $13,310.87 · 120 contributions · $6,000.00 invested · 2016-10 to 2026-10 |
| 10 years · $100/month | $12,000.00 | $36,884.69 | 21.57% | $26,621.74 · 120 contributions · $12,000.00 invested · 2016-10 to 2026-10 |
| 10 years · $500/month | $60,000.00 | $184,423.46 | 21.57% | $133,108.70 · 120 contributions · $60,000.00 invested · 2016-10 to 2026-10 |
| 20 years · $50/month | $12,000.00 | $121,947.07 | 20.00% | $55,895.19 · 240 contributions · $12,000.00 invested · 2006-10 to 2026-10 |
| 20 years · $100/month | $24,000.00 | $243,894.14 | 20.00% | $111,790.38 · 240 contributions · $24,000.00 invested · 2006-10 to 2026-10 |
| 20 years · $500/month | $120,000.00 | $1,219,470.72 | 20.00% | $558,951.89 · 240 contributions · $120,000.00 invested · 2006-10 to 2026-10 |
Asset last price date: 2026-10-23; SPY last price date: 2026-10-23. The latest month may be incomplete. Zero initial investment; contributions start the following month. Monthly observations are estimates, not executable trades. Fees, taxes and FX excluded. Curated surviving assets; delisted companies are absent. Not financial advice. Past performance doesn’t predict future returns.
YOUR INVESTMENT TODAY
$36,884.69
$24,884.69 total gain · 207.37% total return
Amount invested$12,000.00
Annualized (money-weighted IRR)21.57%
Investment multiple3.07×
● Your investment● S&P 500 (SPY)