BWBIX vs. FDFIX

Last updated Aug 1, 2026

BWBIX (Baron WealthBuilder Fund) and FDFIX (Fidelity Flex 500 Index Fund) are both mutual funds - BWBIX is a Diversified Portfolio fund managed by Baron Capital, while FDFIX is a Large Cap Blend Equities fund tracking the Fidelity U.S. Large Cap Index. Over the past 5 years, BWBIX returned 3.22%/yr vs 12.59%/yr for FDFIX. Their correlation of 0.87 means they have usually moved in the same direction. BWBIX charges 0.05%/yr vs 0.00%/yr for FDFIX.

Performance

BWBIX vs. FDFIX - Performance Comparison

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

Returns By Period

In the year-to-date period, BWBIX achieves a 0.78% return, which is significantly lower than FDFIX's 9.08% return.

BWBIX

• 1D: -0.64%
• 1M: -5.41%
• 6M: 2.24%
• YTD: 0.78%
• 1Y: 9.65%
• 3Y*: 10.86%
• 5Y*: 3.22%
• 10Y*: —
• ALL TIME*: 11.99%

FDFIX

• 1D: 1.70%
• 1M: -0.67%
• 6M: 7.78%
• YTD: 9.08%
• 1Y: 20.10%
• 3Y*: 18.85%
• 5Y*: 12.59%
• 10Y*: —
• ALL TIME*: 14.73%

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

Liquidity Comparison

Position	Avg. Volume Value (2W)	Avg. Volume Value (1M)	Avg. Volume Value (3M)
BWBIX Baron WealthBuilder Fund	$0.00	$0.00	$0.00
FDFIX Fidelity Flex 500 Index Fund	$0.00	$0.00	$0.00

BWBIX vs. FDFIX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018
BWBIX Baron WealthBuilder Fund	0.78%	10.23%	19.62%	25.77%	-32.58%	14.76%	62.85%	36.41%	-12.02%
FDFIX Fidelity Flex 500 Index Fund	9.08%	17.59%	25.06%	26.27%	-18.10%	28.69%	18.46%	31.47%	-6.52%

Correlation

The correlation between BWBIX and FDFIX is 0.75, which is moderate. They have sometimes moved together and sometimes differently, sharing some price drivers without tracking each other closely.

	Correlation
Correlation (1Y) Focuses on recent behavior, but can change the most.	0.75
Correlation (3Y) Balances recent behavior with more history.	0.84
Correlation (5Y) Shows whether the relationship held over a longer period.	0.87
Correlation (All Time) Calculated using the full available price history since May 21, 2018	0.87

The correlation between BWBIX and FDFIX shifts across timeframes, from 0.75 (1 year) to 0.87 (5 years), reflecting how their relationship changes across market environments.

Return for Risk

BWBIX vs. FDFIX — Risk / Return Rank

Compare historical risk-adjusted metric ranks over the past 12 months.

BWBIX

BWBIX Risk / Return Rank: 13
BWBIX Sharpe Ratio Rank: 12
BWBIX Sortino Ratio Rank: 13
BWBIX Omega Ratio Rank: 13
BWBIX Calmar Ratio Rank: 14
BWBIX Martin Ratio Rank: 15

FDFIX

FDFIX Risk / Return Rank: 59
FDFIX Sharpe Ratio Rank: 56
FDFIX Sortino Ratio Rank: 53
FDFIX Omega Ratio Rank: 54
FDFIX Calmar Ratio Rank: 61
FDFIX Martin Ratio Rank: 70

The rank (0–100) uses a weighted average of the Sharpe, Sortino, Omega, Calmar, and Martin percentile ranks for the trailing 12 months. Higher means stronger historical risk-adjusted performance within the peer group.

BWBIX vs. FDFIX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Baron WealthBuilder Fund (BWBIX) 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.

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.

	BWBIX	FDFIX	Difference
Sharpe ratio: Return per unit of total volatility	0.46	1.38	-0.92
Sortino ratio: Return per unit of downside risk	0.81	1.93	-1.12
Omega ratio: Gain probability vs. loss probability	1.09	1.25	-0.15
Calmar ratio: Return relative to maximum drawdown	0.64	1.99	-1.36
Martin ratio: Return relative to average drawdown	1.96	8.36	-6.40

BWBIX vs. FDFIX - Sharpe Ratio Comparison

The current BWBIX Sharpe Ratio is 0.46, which is lower than the FDFIX Sharpe Ratio of 1.38. The chart below compares the historical Sharpe Ratios of BWBIX and FDFIX, 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

BWBIX vs. FDFIX - Drawdown Comparison

The maximum BWBIX drawdown since its inception was -39.14%, which is greater than FDFIX's maximum drawdown of -33.77%. Use the drawdown chart below to compare losses from any high point for BWBIX and FDFIX.

Drawdown Indicators

	BWBIX	FDFIX	Difference
Max Drawdown Largest peak-to-trough decline	-39.14%	-33.77%	-5.37%
Max Drawdown (1Y) Largest decline over 1 year	-11.65%	-8.99%	-2.66%
Max Drawdown (3Y) Largest decline over 3 years	-21.59%	-18.76%	-2.83%
Max Drawdown (5Y) Largest decline over 5 years	-39.14%	-24.51%	-14.63%
Current Drawdown Current decline from peak	-5.90%	-2.20%	-3.70%
Average Drawdown Average peak-to-trough decline	-11.55%	-4.53%	-7.02%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.79%	2.14%	+1.65%

Volatility

BWBIX vs. FDFIX - Volatility Comparison

Baron WealthBuilder Fund (BWBIX) has a higher volatility of 4.30% compared to Fidelity Flex 500 Index Fund (FDFIX) at 3.50%. This indicates that BWBIX's price experiences larger fluctuations and is considered to be riskier than FDFIX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	BWBIX	FDFIX	Difference
Volatility (1M) Calculated over the trailing 1-month period	4.30%	3.50%	+0.80%
Volatility (6M) Calculated over the trailing 6-month period	12.24%	10.20%	+2.04%
Volatility (1Y) Calculated over the trailing 1-year period	16.10%	13.02%	+3.08%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	21.31%	17.07%	+4.24%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	23.09%	18.53%	+4.56%

BWBIX vs. FDFIX - Expense Ratio Comparison

BWBIX has a 0.05% expense ratio, which is higher than FDFIX's 0.00% expense ratio. However, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.

Dividends

BWBIX vs. FDFIX - Dividend Comparison

BWBIX's dividend yield for the trailing twelve months is around 7.55%, more than FDFIX's 1.07% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017
BWBIX Baron WealthBuilder Fund	7.55%	7.61%	0.77%	0.06%	3.21%	3.75%	1.24%	3.51%	0.14%	0.00%
FDFIX Fidelity Flex 500 Index Fund	1.07%	1.11%	1.26%	1.48%	1.70%	1.27%	1.52%	1.78%	2.16%	0.50%

Frequently Asked Questions

Can I hold both BWBIX and FDFIX in my portfolio?

BWBIX and FDFIX have a correlation of 0.75, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, BWBIX or FDFIX?

BWBIX has higher volatility (4.30%) compared to FDFIX (3.50%). In terms of maximum drawdown, BWBIX dropped -39.14% vs FDFIX's -33.77%.

Which has better risk-adjusted returns?

FDFIX currently has the higher Sharpe Ratio (1.38 vs 0.46), 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.