TANDX vs. FDFIX

Last updated Apr 1, 2026

Compare and contrast key facts about Castle Tandem Fund (TANDX) and Fidelity Flex 500 Index Fund (FDFIX).

TANDX is managed by Castle Investment Management. It was launched on Mar 15, 2019. FDFIX is managed by Fidelity. It was launched on Mar 9, 2017.

Performance

TANDX vs. FDFIX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Castle Tandem Fund (TANDX) and Fidelity Flex 500 Index Fund (FDFIX). The values are adjusted to include any dividend payments, if applicable.

TANDX vs. FDFIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019
TANDX Castle Tandem Fund	-9.28%	3.67%	7.66%	8.42%	-7.87%	19.03%	13.39%	12.57%
FDFIX Fidelity Flex 500 Index Fund	-7.27%	17.59%	25.06%	26.27%	-18.10%	28.69%	18.46%	17.08%

Returns By Period

In the year-to-date period, TANDX achieves a -9.28% return, which is significantly lower than FDFIX's -7.27% return.

TANDX

• 1D: 0.79%
• 1M: -6.24%
• YTD: -9.28%
• 6M: -10.00%
• 1Y: -10.50%
• 3Y*: 2.42%
• 5Y*: 3.29%
• 10Y*: —

FDFIX

• 1D: -0.33%
• 1M: -7.59%
• YTD: -7.27%
• 6M: -4.96%
• 1Y: 13.90%
• 3Y*: 17.02%
• 5Y*: 11.31%
• 10Y*: —

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

TANDX vs. FDFIX - Expense Ratio Comparison

TANDX has a 1.59% expense ratio, which is higher than FDFIX's 0.00% expense ratio.

TANDX

Castle Tandem Fund

FDFIX

Fidelity Flex 500 Index Fund

Return for Risk

TANDX vs. FDFIX — Risk / Return Rank

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

TANDX

TANDX Risk / Return Rank: 0
TANDX Sharpe Ratio Rank: 1
TANDX Sortino Ratio Rank: 0
TANDX Omega Ratio Rank: 1
TANDX Calmar Ratio Rank: 0
TANDX Martin Ratio Rank: 0

FDFIX

FDFIX Risk / Return Rank: 42
FDFIX Sharpe Ratio Rank: 39
FDFIX Sortino Ratio Rank: 43
FDFIX Omega Ratio Rank: 47
FDFIX Calmar Ratio Rank: 36
FDFIX Martin Ratio Rank: 46

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.

TANDX vs. FDFIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Castle Tandem Fund (TANDX) and Fidelity Flex 500 Index Fund (FDFIX). 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.

	TANDX	FDFIX	Difference
Sharpe ratio Return per unit of total volatility	-0.81	0.81	-1.62
Sortino ratio Return per unit of downside risk	-1.07	1.26	-2.33
Omega ratio Gain probability vs. loss probability	0.86	1.19	-0.33
Calmar ratio Return relative to maximum drawdown	-0.79	0.96	-1.75
Martin ratio Return relative to average drawdown	-2.33	4.59	-6.92
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

TANDX vs. FDFIX - Sharpe Ratio Comparison

The current TANDX Sharpe Ratio is -0.81, which is lower than the FDFIX Sharpe Ratio of 0.81. The chart below compares the historical Sharpe Ratios of TANDX and FDFIX, offering insights into how both investments have performed under varying market conditions. These values are calculated using daily returns over the previous 12 months.

Sharpe Ratios by Period

	TANDX	FDFIX	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	-0.81	0.81	-1.62
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.00	0.67	-0.67
Sharpe Ratio (All Time) Calculated using the full available price history	0.01	0.71	-0.71

Correlation

The correlation between TANDX and FDFIX is 0.78, which is considered to be high. That indicates a strong positive relationship between their price movements. Having highly-correlated positions in a portfolio may signal a lack of diversification, potentially leading to increased risk during market downturns.

Dividends

TANDX vs. FDFIX - Dividend Comparison

TANDX's dividend yield for the trailing twelve months is around 6.80%, more than FDFIX's 1.20% yield.

	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017
TANDX Castle Tandem Fund	6.80%	6.17%	3.71%	2.10%	1.48%	4.57%	0.33%	0.37%	0.00%	0.00%
FDFIX Fidelity Flex 500 Index Fund	1.20%	1.11%	1.26%	1.48%	1.70%	1.27%	1.52%	1.78%	2.16%	0.50%

Drawdowns

TANDX vs. FDFIX - Drawdown Comparison

The maximum TANDX drawdown since its inception was -95.17%, which is greater than FDFIX's maximum drawdown of -33.77%. Use the drawdown chart below to compare losses from any high point for TANDX and FDFIX.

Drawdown Indicators

	TANDX	FDFIX	Difference
Max Drawdown Largest peak-to-trough decline	-95.17%	-33.77%	-61.40%
Max Drawdown (1Y) Largest decline over 1 year	-13.14%	-12.13%	-1.01%
Max Drawdown (5Y) Largest decline over 5 years	-95.17%	-24.51%	-70.66%
Current Drawdown Current decline from peak	-95.13%	-8.99%	-86.14%
Average Drawdown Average peak-to-trough decline	-18.89%	-4.64%	-14.25%
Ulcer Index Depth and duration of drawdowns from previous peaks	4.43%	2.60%	+1.83%

Volatility

TANDX vs. FDFIX - Volatility Comparison

The current volatility for Castle Tandem Fund (TANDX) is 3.00%, while Fidelity Flex 500 Index Fund (FDFIX) has a volatility of 4.22%. This indicates that TANDX experiences smaller price fluctuations and is considered to be less risky than FDFIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	TANDX	FDFIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.00%	4.22%	-1.22%
Volatility (6M) Calculated over the trailing 6-month period	7.28%	9.16%	-1.88%
Volatility (1Y) Calculated over the trailing 1-year period	12.04%	18.20%	-6.16%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	1,010.25%	16.91%	+993.34%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	852.68%	18.68%	+834.00%