RCKSX vs. FZROX

Last updated Jun 24, 2026

RCKSX (Rock Oak Core Growth Fund) and FZROX (Fidelity ZERO Total Market Index Fund) are both Large Cap Blend Equities funds. Over the past 5 years, RCKSX returned 8.00%/yr vs 12.61%/yr for FZROX. Their correlation of 0.86 suggests significant overlap in exposure. RCKSX charges 1.25%/yr vs 0.00%/yr for FZROX.

Performance

RCKSX vs. FZROX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Rock Oak Core Growth Fund (RCKSX) and Fidelity ZERO Total Market Index Fund (FZROX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, RCKSX achieves a 15.47% return, which is significantly higher than FZROX's 10.41% return.

RCKSX

• 1D: 0.00%
• 1M: 0.60%
• YTD: 15.47%
• 6M: 13.64%
• 1Y: 20.17%
• 3Y*: 19.37%
• 5Y*: 8.00%
• 10Y*: 11.43%

FZROX

• 1D: -0.31%
• 1M: 0.62%
• YTD: 10.41%
• 6M: 9.30%
• 1Y: 26.02%
• 3Y*: 21.31%
• 5Y*: 12.61%
• 10Y*: —

*Multi-year figures are annualized to reflect compound growth (CAGR)

RCKSX vs. FZROX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018
RCKSX Rock Oak Core Growth Fund	15.47%	12.99%	15.12%	15.57%	-18.09%	9.96%	13.75%	19.05%	-17.81%
FZROX Fidelity ZERO Total Market Index Fund	10.41%	17.23%	23.94%	26.20%	-19.21%	26.00%	20.51%	31.15%	-12.72%

Correlation

The correlation between RCKSX and FZROX is 0.65, which is moderate. They share some common price drivers but move independently often enough to provide real diversification benefit when combined.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.65
Correlation (3Y) Calculated over the trailing 3-year period	0.73
Correlation (5Y) Calculated over the trailing 5-year period	0.83
Correlation (All Time) Calculated using the full available price history since Aug 16, 2018	0.86

Over the past year, the correlation between RCKSX and FZROX has dropped to 0.65 - well below their long-term average of 0.86, suggesting their price drivers have been diverging.

Return for Risk

RCKSX vs. FZROX — Risk / Return Rank

Compare risk-adjusted metric ranks to identify better-performing investments over the past 12 months.

RCKSX

RCKSX Risk / Return Rank: 63
RCKSX Sharpe Ratio Rank: 48
RCKSX Sortino Ratio Rank: 49
RCKSX Omega Ratio Rank: 39
RCKSX Calmar Ratio Rank: 95
RCKSX Martin Ratio Rank: 85

FZROX

FZROX Risk / Return Rank: 65
FZROX Sharpe Ratio Rank: 62
FZROX Sortino Ratio Rank: 56
FZROX Omega Ratio Rank: 57
FZROX Calmar Ratio Rank: 70
FZROX Martin Ratio Rank: 79

The rank (0–100) shows how this investment's returns compare to the risk taken. Higher = better. Based on the past 12 months of data, combining Sharpe, Sortino, and other metrics used by quantitative funds and institutional investors.

RCKSX vs. FZROX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Rock Oak Core Growth Fund (RCKSX) and Fidelity ZERO Total Market Index Fund (FZROX). 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.

	RCKSX	FZROX	Difference
Sharpe ratio: Return per unit of total volatility	1.89	2.13	-0.24
Sortino ratio: Return per unit of downside risk	2.72	2.88	-0.16
Omega ratio: Gain probability vs. loss probability	1.31	1.38	-0.07
Calmar ratio: Return relative to maximum drawdown	5.35	3.08	+2.27
Martin ratio: Return relative to average drawdown	14.75	13.77	+0.98

RCKSX vs. FZROX - Sharpe Ratio Comparison

The current RCKSX Sharpe Ratio is 1.89, which is comparable to the FZROX Sharpe Ratio of 2.13. The chart below compares the historical Sharpe Ratios of RCKSX and FZROX, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Drawdowns

RCKSX vs. FZROX - Drawdown Comparison

The maximum RCKSX drawdown since its inception was -57.88%, which is greater than FZROX's maximum drawdown of -34.96%. Use the drawdown chart below to compare losses from any high point for RCKSX and FZROX.

Drawdown Indicators

	RCKSX	FZROX	Difference
Max Drawdown Largest peak-to-trough decline	-57.88%	-34.96%	-22.92%
Max Drawdown (1Y) Largest decline over 1 year	-4.14%	-8.89%	+4.75%
Max Drawdown (3Y) Largest decline over 3 years	-18.22%	-19.38%	+1.16%
Max Drawdown (5Y) Largest decline over 5 years	-22.54%	-25.12%	+2.58%
Max Drawdown (10Y) Largest decline over 10 years	-33.10%	—	—
Current Drawdown Current decline from peak	-0.46%	-1.44%	+0.98%
Average Drawdown Average peak-to-trough decline	-9.48%	-5.48%	-4.00%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.50%	1.98%	-0.48%

Volatility

RCKSX vs. FZROX - Volatility Comparison

The current volatility for Rock Oak Core Growth Fund (RCKSX) is 3.29%, while Fidelity ZERO Total Market Index Fund (FZROX) has a volatility of 4.82%. This indicates that RCKSX experiences smaller price fluctuations and is considered to be less risky than FZROX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	RCKSX	FZROX	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.29%	4.82%	-1.53%
Volatility (6M) Calculated over the trailing 6-month period	8.07%	10.10%	-2.03%
Volatility (1Y) Calculated over the trailing 1-year period	11.75%	12.88%	-1.13%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	15.64%	17.53%	-1.89%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	17.55%	20.13%	-2.58%

RCKSX vs. FZROX - Expense Ratio Comparison

RCKSX has a 1.25% expense ratio, which is higher than FZROX's 0.00% expense ratio.

Dividends

RCKSX vs. FZROX - Dividend Comparison

RCKSX's dividend yield for the trailing twelve months is around 5.42%, more than FZROX's 0.93% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FZROX Fidelity ZERO Total Market Index Fund	0.93%	1.02%	1.16%	1.36%	1.57%	1.25%	1.27%	1.51%	0.00%	0.00%	0.00%	0.00%
RCKSX Rock Oak Core Growth Fund	5.42%	6.26%	0.47%	0.71%	1.00%	4.31%	16.56%	3.18%	0.59%	5.91%	0.70%	3.21%

Frequently Asked Questions

Can I hold both RCKSX and FZROX in my portfolio?

RCKSX and FZROX have a correlation of 0.65, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, RCKSX or FZROX?

FZROX has higher volatility (4.82%) compared to RCKSX (3.29%). In terms of maximum drawdown, RCKSX dropped -57.88% vs FZROX's -34.96%.

Which has better risk-adjusted returns?

FZROX currently has the higher Sharpe Ratio (2.13 vs 1.89), 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.