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ISIN
US0930014859
CUSIP
093001485
Inception Date
Dec 27, 1999
Min. Investment
$500,000
Distribution Policy
Distributing
Asset Class
Equity
Asset Class Size
Small-Cap
Asset Class Style
Growth

Share Price Chart


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Performance

WBSIX Performance Chart

William Blair Small Cap Growth Fund (WBSIX) is up 19.2% since the beginning of the year. WBSIX is currently trading at $40 per share. Investors who bought $1,000 worth of WBSIX shares 5 years ago would now be looking at an investment worth $1,519.


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S&P 500 Index

Returns By Period

William Blair Small Cap Growth Fund (WBSIX) has returned 19.23% so far this year and 33.70% over the past 12 months. Looking at the last ten years, WBSIX has achieved an annualized return of 15.09%, outperforming the S&P 500 Index benchmark, which averaged 13.88% per year.


William Blair Small Cap Growth Fund

1D
2.77%
1M
6.13%
YTD
19.23%
6M
16.34%
1Y
33.70%
3Y*
20.12%
5Y*
8.72%
10Y*
15.09%

Benchmark (S&P 500 Index)

1D
-0.37%
1M
-0.01%
YTD
9.16%
6M
8.64%
1Y
25.22%
3Y*
19.78%
5Y*
11.99%
10Y*
13.88%
*Multi-year figures are annualized to reflect compound growth (CAGR)

WBSIX Monthly Returns History

Based on dividend-adjusted daily data since Dec 27, 1999, WBSIX's average daily return is +0.06%, while the average monthly return is +1.21%. At this rate, an investment would double in approximately 4.8 years.

Historically, 61% of months were positive and 39% were negative. The best month was Feb 2000 with a return of +45.2%, while the worst month was Oct 2008 at -22.8%. The longest winning streak lasted 8 consecutive months, and the longest losing streak was 5 months.

On a daily basis, WBSIX closed higher 53% of trading days. The best single day was Dec 19, 2024 with a return of +11.2%, while the worst single day was Mar 16, 2020 at -13.5%.


JanFebMarAprMayJunJulAugSepOctNovDecTotal
20264.34%1.22%-6.94%12.47%3.66%4.05%19.23%
20252.57%-5.90%-7.83%-2.89%3.54%5.91%0.42%6.01%-0.84%-0.76%3.36%0.45%3.03%
2024-4.11%9.04%2.11%-5.97%7.26%0.14%5.88%-0.30%0.59%-2.89%12.18%6.51%32.88%
202310.32%-1.50%-1.91%-1.48%-0.90%6.95%3.12%-4.28%-4.66%-6.94%8.43%10.12%16.38%
2022-12.45%1.07%2.35%-11.80%-2.54%-7.36%10.05%-1.85%-7.01%8.87%4.90%-5.07%-21.46%
20211.50%7.03%-0.70%3.51%-1.68%2.94%-1.42%4.20%-2.52%5.41%-5.32%-0.25%12.64%

Benchmark Metrics

William Blair Small Cap Growth Fund has an annualized alpha of 6.76%, beta of 1.00, and R2 of 0.70 versus S&P 500 Index. Calculated based on daily prices since December 27, 1999.

  • This fund captured 133.98% of S&P 500 Index gains and 102.86% of its losses - amplifying both gains and losses, but participating more in upside than downside.
  • This fund generated an annualized alpha of 6.76% versus S&P 500 Index - delivering returns beyond what market exposure alone would predict.
  • With beta of 1.00 and R2 of 0.70, this fund moves broadly in line with S&P 500 Index - much of its variation is explained by market exposure rather than independent behavior.

Alpha
6.76%
Beta
1.00
0.70
Upside Capture
133.98%
Downside Capture
102.86%

Expense Ratio

WBSIX has a high expense ratio of 1.25%, indicating above-average management fees.


Return for Risk

Risk / Return Rank

WBSIX ranks 40 for risk / return — on par with similar mutual funds. You're getting a typical balance of risk and reward. Not a standout, but not a red flag either — a reasonable choice if other factors align with your goals.


WBSIX Risk / Return Rank: 4040
Overall Rank
WBSIX Sharpe Ratio Rank: 3535
Sharpe Ratio Rank
WBSIX Sortino Ratio Rank: 3535
Sortino Ratio Rank
WBSIX Omega Ratio Rank: 3131
Omega Ratio Rank
WBSIX Calmar Ratio Rank: 5151
Calmar Ratio Rank
WBSIX Martin Ratio Rank: 4848
Martin Ratio Rank
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.

Return / Risk — by metrics

The table below present risk-adjusted performance metrics for William Blair Small Cap Growth Fund (WBSIX) and compare them to S&P 500 Index.

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.


WBSIXBenchmarkDifference
Sharpe ratioReturn per unit of total volatility

-0.42

Sortino ratioReturn per unit of downside risk

-0.44

Omega ratioGain probability vs. loss probability

1.27

1.37

-0.10

Calmar ratioReturn relative to maximum drawdown

2.61

2.78

-0.17

Martin ratioReturn relative to average drawdown

9.39

12.44

-3.05

Dividends

Dividend History

William Blair Small Cap Growth Fund provided a 6.28% dividend yield over the last twelve months, with an annual payout of $2.54 per share.


0.00%5.00%10.00%15.00%20.00%$0.00$2.00$4.00$6.00$8.0020152016201720182019202020212022202320242025
Dividends
Dividend Yield
PeriodTTM20252024202320222021202020192018201720162015
Dividend$2.54$2.54$7.12$0.50$1.01$6.70$3.83$0.64$3.27$5.00$1.48$1.99

Dividend yield

6.28%7.49%20.14%1.53%3.55%17.85%9.73%2.07%12.60%16.89%5.42%8.25%

Monthly Dividends

The table displays the monthly dividend distributions for William Blair Small Cap Growth Fund. The dividends shown in the table have been adjusted to account for any splits that may have occurred.


JanFebMarAprMayJunJulAugSepOctNovDecTotal
2026$0.00$0.00$0.00$0.00$0.00$0.00$0.00
2025$0.00$0.00$0.00$0.00$0.00$0.00$0.00$0.00$0.00$0.00$0.00$2.54$2.54
2024$0.00$0.00$0.00$0.00$0.00$0.00$0.00$0.00$0.00$0.00$0.00$7.12$7.12
2023$0.00$0.00$0.00$0.00$0.00$0.00$0.00$0.00$0.00$0.00$0.00$0.50$0.50
2022$0.00$0.00$0.00$0.00$0.00$0.00$0.00$0.00$0.00$0.00$0.00$1.01$1.01
2021$0.00$0.00$0.00$0.00$0.00$0.00$0.00$0.00$0.00$0.00$0.00$6.70$6.70

Drawdowns

Drawdowns Chart

The Drawdowns chart displays portfolio losses from any high point along the way. Drawdowns are calculated considering price movements and all distributions paid, if any.


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Worst Drawdowns

The table below displays the maximum drawdowns of the William Blair Small Cap Growth Fund. A maximum drawdown is a measure of risk, indicating the largest reduction in portfolio value due to a series of losing trades.

The maximum drawdown for the William Blair Small Cap Growth Fund was 62.35%, occurring on Nov 20, 2008. Recovery took 1045 trading sessions.


Related event

Drawdown

Fall

Recovery

Underwater

Financial crisis2007–2009
-62.35%Nov 2008
1y 4mo4y 1mo
5y 6moJul 2007 - Jan 2013
COVID crash2020
-39.16%Mar 2020
26d4mo 20d
5mo 16dFeb 2020 - Aug 2020
Bear market2022
-38.13%Jun 2022
7mo 9d2y 4mo
3yNov 2021 - Nov 2024
Dot-com crash2000–2002
-32.68%Apr 2001
7mo 5d2y 2mo
2y 9moSep 2000 - Jun 2003
Dot-com crash2000–2002
-32.42%Apr 2000
1mo 2d4mo 19d
5mo 21dMar 2000 - Aug 2000

Drawdown Indicators


WBSIXBenchmarkDifference

Max Drawdown

Largest peak-to-trough decline

-62.35%

-56.78%

-5.57%

Max Drawdown (1Y)

Largest decline over 1 year

-12.75%

-9.10%

-3.65%

Max Drawdown (3Y)

Largest decline over 3 years

-24.76%

-18.90%

-5.86%

Max Drawdown (5Y)

Largest decline over 5 years

-38.13%

-25.43%

-12.70%

Max Drawdown (10Y)

Largest decline over 10 years

-39.16%

-33.92%

-5.24%

Current Drawdown

Current decline from peak

0.00%

-1.80%

+1.80%

Average Drawdown

Average peak-to-trough decline

-11.12%

-10.71%

-0.41%

Ulcer Index

Depth and duration of drawdowns from previous peaks

3.53%

2.03%

+1.50%

Volatility

Volatility Chart

The chart below shows the rolling one-month volatility.


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Portfolio Analyzer

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