POSKX vs. SPY
POSKX (PrimeCap Odyssey Stock Fund) and SPY (State Street SPDR S&P 500 ETF) are both funds - POSKX is a Large Cap Blend Equities fund managed by PRIMECAP Odyssey Funds, while SPY is a S&P 500 fund tracking the S&P 500 Index. Over the past 10 years, POSKX returned 16.68%/yr vs 15.70%/yr for SPY. Their correlation of 0.93 suggests significant overlap in exposure. POSKX charges 0.65%/yr vs 0.09%/yr for SPY.
Performance
POSKX vs. SPY - Performance Comparison
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Returns By Period
In the year-to-date period, POSKX achieves a 25.29% return, which is significantly higher than SPY's 9.74% return. Over the past 10 years, POSKX has outperformed SPY with an annualized return of 16.68%, while SPY has yielded a comparatively lower 15.70% annualized return.
POSKX
- 1D
- 1.81%
- 1M
- 4.82%
- YTD
- 25.29%
- 6M
- 23.99%
- 1Y
- 52.59%
- 3Y*
- 24.45%
- 5Y*
- 16.90%
- 10Y*
- 16.68%
SPY
- 1D
- -0.31%
- 1M
- 0.09%
- YTD
- 9.74%
- 6M
- 9.27%
- 1Y
- 26.65%
- 3Y*
- 21.27%
- 5Y*
- 13.51%
- 10Y*
- 15.70%
POSKX vs. SPY - Yearly Performance Comparison
| 2026 (YTD) | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | |
|---|---|---|---|---|---|---|---|---|---|---|
POSKX PrimeCap Odyssey Stock Fund | 25.29% | 25.73% | 12.77% | 21.18% | -11.12% | 32.48% | 10.13% | 27.15% | -7.19% | 25.99% |
SPY State Street SPDR S&P 500 ETF | 9.74% | 17.72% | 24.89% | 26.18% | -18.18% | 28.73% | 18.33% | 31.22% | -4.57% | 21.71% |
Correlation
The correlation between POSKX and SPY is 0.82, indicating a strong positive relationship between their price movements. Combining them offers limited diversification - they tend to fall together during downturns.
| Correlation | |
|---|---|
Correlation (1Y) Calculated over the trailing 1-year period | 0.82 |
Correlation (3Y) Calculated over the trailing 3-year period | 0.86 |
Correlation (5Y) Calculated over the trailing 5-year period | 0.90 |
Correlation (10Y) Calculated over the trailing 10-year period | 0.90 |
Correlation (All Time) Calculated using the full available price history since Nov 2, 2004 | 0.93 |
The correlation between POSKX and SPY shifts across timeframes, from 0.82 (1 year) to 0.93 (all time), reflecting how their relationship changes across market environments.
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Return for Risk
POSKX vs. SPY — Risk / Return Rank
POSKX
SPY
POSKX vs. SPY - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for PrimeCap Odyssey Stock Fund (POSKX) and State Street SPDR S&P 500 ETF (SPY). Risk-adjusted metrics are performance indicators that assess an investment's returns in relation to its risk, enabling a more accurate comparison of different investment options.
Values are calculated on a 1-year rolling basis and updated daily. Risk-adjusted metrics are more stable over longer periods — use the period switch above to explore them.
| POSKX | SPY | Difference | |
|---|---|---|---|
| Sharpe ratioReturn per unit of total volatility | +0.92 | ||
| Sortino ratioReturn per unit of downside risk | +1.30 | ||
| Omega ratioGain probability vs. loss probability | 1.54 | 1.39 | +0.15 |
| Calmar ratioReturn relative to maximum drawdown | 5.21 | 3.01 | +2.20 |
| Martin ratioReturn relative to average drawdown | 21.60 | 13.54 | +8.07 |
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Drawdowns
POSKX vs. SPY - Drawdown Comparison
The maximum POSKX drawdown since its inception was -50.18%, smaller than the maximum SPY drawdown of -55.19%. Use the drawdown chart below to compare losses from any high point for POSKX and SPY.
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Drawdown Indicators
| POSKX | SPY | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -50.18% | -55.19% | +5.01% |
Max Drawdown (1Y)Largest decline over 1 year | -9.99% | -8.88% | -1.11% |
Max Drawdown (3Y)Largest decline over 3 years | -20.25% | -18.76% | -1.49% |
Max Drawdown (5Y)Largest decline over 5 years | -22.96% | -24.50% | +1.54% |
Max Drawdown (10Y)Largest decline over 10 years | -36.88% | -33.72% | -3.16% |
Current DrawdownCurrent decline from peak | -0.46% | -1.75% | +1.29% |
Average DrawdownAverage peak-to-trough decline | -6.14% | -9.04% | +2.90% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 2.40% | 1.97% | +0.43% |
Volatility
POSKX vs. SPY - Volatility Comparison
PrimeCap Odyssey Stock Fund (POSKX) has a higher volatility of 6.92% compared to State Street SPDR S&P 500 ETF (SPY) at 4.64%. This indicates that POSKX's price experiences larger fluctuations and is considered to be riskier than SPY based on this measure. The chart below showcases a comparison of their rolling one-month volatility.
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Volatility by Period
| POSKX | SPY | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 6.92% | 4.64% | +2.28% |
Volatility (6M)Calculated over the trailing 6-month period | 13.87% | 9.75% | +4.12% |
Volatility (1Y)Calculated over the trailing 1-year period | 16.89% | 12.43% | +4.46% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 18.05% | 17.14% | +0.91% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 19.08% | 17.99% | +1.09% |
POSKX vs. SPY - Expense Ratio Comparison
POSKX has a 0.65% expense ratio, which is higher than SPY's 0.09% expense ratio.
Dividends
POSKX vs. SPY - Dividend Comparison
POSKX's dividend yield for the trailing twelve months is around 21.90%, more than SPY's 1.01% yield.
| Position | TTM | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
POSKX PrimeCap Odyssey Stock Fund | 21.90% | 27.44% | 18.13% | 10.14% | 12.13% | 14.58% | 7.85% | 6.03% | 3.03% | 2.17% | 2.93% | 1.92% |
SPY State Street SPDR S&P 500 ETF | 1.01% | 1.07% | 1.21% | 1.40% | 1.65% | 1.20% | 1.52% | 1.75% | 2.04% | 1.80% | 2.03% | 2.06% |
Frequently Asked Questions
POSKX and SPY have a correlation of 0.82, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.
POSKX has higher volatility (6.92%) compared to SPY (4.64%). In terms of maximum drawdown, POSKX dropped -50.18% vs SPY's -55.19%.
POSKX currently has the higher Sharpe Ratio (3.08 vs 2.16), meaning it's delivered slightly more return per unit of risk over the trailing 12 months. However, this ranking shifts over time - use the Risk/Return Score above for a more comprehensive view that combines Sharpe, Sortino, and other measures used by quantitative funds.
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