PAI vs. VSTBX

Last updated Jun 24, 2026

PAI (Western Asset Investment Grade Income Fund Inc.) and VSTBX (Vanguard Short-Term Corporate Bond Index Fund Institutional Shares) are both Corporate Bonds funds. Over the past 10 years, PAI returned 3.19%/yr vs 2.97%/yr for VSTBX. At a 0.21 correlation, their price movements are largely independent.

Performance

PAI vs. VSTBX - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Western Asset Investment Grade Income Fund Inc. (PAI) and Vanguard Short-Term Corporate Bond Index Fund Institutional Shares (VSTBX). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, PAI achieves a -1.19% return, which is significantly lower than VSTBX's 0.66% return. Over the past 10 years, PAI has outperformed VSTBX with an annualized return of 3.19%, while VSTBX has yielded a comparatively lower 2.97% annualized return.

PAI

• 1D: 0.10%
• 1M: 0.64%
• YTD: -1.19%
• 6M: -0.77%
• 1Y: 2.39%
• 3Y*: 6.50%
• 5Y*: 0.06%
• 10Y*: 3.19%

VSTBX

• 1D: -0.08%
• 1M: 0.26%
• YTD: 0.66%
• 6M: 0.85%
• 1Y: 4.03%
• 3Y*: 5.68%
• 5Y*: 2.43%
• 10Y*: 2.97%

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

PAI vs. VSTBX - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
PAI Western Asset Investment Grade Income Fund Inc.	-1.19%	5.34%	9.17%	9.09%	-22.50%	1.89%	6.71%	23.16%	-12.35%	15.76%
VSTBX Vanguard Short-Term Corporate Bond Index Fund Institutional Shares	0.66%	6.75%	5.37%	6.17%	-5.73%	-0.41%	5.07%	9.68%	0.92%	2.48%

Correlation

The correlation between PAI and VSTBX is 0.47, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.47
Correlation (3Y) Calculated over the trailing 3-year period	0.42
Correlation (5Y) Calculated over the trailing 5-year period	0.40
Correlation (10Y) Calculated over the trailing 10-year period	0.28
Correlation (All Time) Calculated using the full available price history since Nov 19, 2009	0.21

Over the past year, PAI and VSTBX have become more correlated (0.47) than their long-term average of 0.21, meaning their price movements have been converging.

Return for Risk

PAI vs. VSTBX — Risk / Return Rank

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

PAI

PAI Risk / Return Rank: 5
PAI Sharpe Ratio Rank: 5
PAI Sortino Ratio Rank: 5
PAI Omega Ratio Rank: 5
PAI Calmar Ratio Rank: 5
PAI Martin Ratio Rank: 4

VSTBX

VSTBX Risk / Return Rank: 77
VSTBX Sharpe Ratio Rank: 77
VSTBX Sortino Ratio Rank: 83
VSTBX Omega Ratio Rank: 78
VSTBX Calmar Ratio Rank: 74
VSTBX Martin Ratio Rank: 69

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.

PAI vs. VSTBX - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Western Asset Investment Grade Income Fund Inc. (PAI) and Vanguard Short-Term Corporate Bond Index Fund Institutional Shares (VSTBX). 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.

	PAI	VSTBX	Difference
Sharpe ratio: Return per unit of total volatility	0.30	2.36	-2.06
Sortino ratio: Return per unit of downside risk	0.47	3.61	-3.15
Omega ratio: Gain probability vs. loss probability	1.06	1.47	-0.41
Calmar ratio: Return relative to maximum drawdown	0.31	3.20	-2.89
Martin ratio: Return relative to average drawdown	0.67	12.56	-11.89

PAI vs. VSTBX - Sharpe Ratio Comparison

The current PAI Sharpe Ratio is 0.30, which is lower than the VSTBX Sharpe Ratio of 2.36. The chart below compares the historical Sharpe Ratios of PAI and VSTBX, 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

PAI vs. VSTBX - Drawdown Comparison

The maximum PAI drawdown since its inception was -39.03%, which is greater than VSTBX's maximum drawdown of -9.34%. Use the drawdown chart below to compare losses from any high point for PAI and VSTBX.

Drawdown Indicators

	PAI	VSTBX	Difference
Max Drawdown Largest peak-to-trough decline	-39.03%	-9.34%	-29.69%
Max Drawdown (1Y) Largest decline over 1 year	-7.79%	-1.31%	-6.48%
Max Drawdown (3Y) Largest decline over 3 years	-8.87%	-1.31%	-7.56%
Max Drawdown (5Y) Largest decline over 5 years	-33.71%	-9.34%	-24.37%
Max Drawdown (10Y) Largest decline over 10 years	-33.71%	-9.34%	-24.37%
Current Drawdown Current decline from peak	-11.29%	-0.32%	-10.97%
Average Drawdown Average peak-to-trough decline	-7.13%	-0.95%	-6.18%
Ulcer Index Depth and duration of drawdowns from previous peaks	3.56%	0.33%	+3.23%

Volatility

PAI vs. VSTBX - Volatility Comparison

Western Asset Investment Grade Income Fund Inc. (PAI) has a higher volatility of 1.18% compared to Vanguard Short-Term Corporate Bond Index Fund Institutional Shares (VSTBX) at 0.63%. This indicates that PAI's price experiences larger fluctuations and is considered to be riskier than VSTBX based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	PAI	VSTBX	Difference
Volatility (1M) Calculated over the trailing 1-month period	1.18%	0.63%	+0.55%
Volatility (6M) Calculated over the trailing 6-month period	5.49%	1.35%	+4.14%
Volatility (1Y) Calculated over the trailing 1-year period	7.98%	1.78%	+6.20%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	11.99%	2.72%	+9.27%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	15.43%	2.38%	+13.05%

Dividends

PAI vs. VSTBX - Dividend Comparison

PAI's dividend yield for the trailing twelve months is around 5.22%, more than VSTBX's 4.45% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
PAI Western Asset Investment Grade Income Fund Inc.	5.22%	5.45%	4.83%	4.67%	4.82%	3.57%	3.82%	4.43%	5.23%	4.36%	4.82%	5.30%
VSTBX Vanguard Short-Term Corporate Bond Index Fund Institutional Shares	4.45%	4.34%	4.29%	3.09%	2.00%	1.80%	2.27%	5.40%	2.67%	2.27%	1.96%	2.25%

Frequently Asked Questions

Can I hold both PAI and VSTBX in my portfolio?

PAI and VSTBX have a correlation of 0.47, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, PAI or VSTBX?

PAI has higher volatility (1.18%) compared to VSTBX (0.63%). In terms of maximum drawdown, PAI dropped -39.03% vs VSTBX's -9.34%.

Which has better risk-adjusted returns?

VSTBX currently has the higher Sharpe Ratio (2.36 vs 0.30), 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.