TAN vs. COST

Last updated Jun 14, 2026

TAN (Invesco Solar ETF) is Alternative Energy Equities fund tracking the MAC Global Solar Energy Index, while COST (Costco Wholesale Corporation) is a stock. Over the past 10 years, TAN returned 13.06%/yr vs 22.27%/yr for COST. At a 0.26 correlation, their price movements are largely independent.

Performance

TAN vs. COST - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Invesco Solar ETF (TAN) and Costco Wholesale Corporation (COST). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, TAN achieves a 28.32% return, which is significantly higher than COST's 14.24% return. Over the past 10 years, TAN has underperformed COST with an annualized return of 13.06%, while COST has yielded a comparatively higher 22.27% annualized return.

TAN

• 1D: 1.17%
• 1M: -2.96%
• YTD: 28.32%
• 6M: 31.75%
• 1Y: 80.24%
• 3Y*: -4.29%
• 5Y*: -4.50%
• 10Y*: 13.06%

COST

• 1D: 0.68%
• 1M: -6.35%
• YTD: 14.24%
• 6M: 11.38%
• 1Y: -0.24%
• 3Y*: 25.12%
• 5Y*: 22.12%
• 10Y*: 22.27%

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

TAN vs. COST - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
TAN Invesco Solar ETF	28.32%	48.31%	-37.61%	-26.79%	-5.24%	-25.10%	233.96%	66.53%	-25.67%	54.38%
COST Costco Wholesale Corporation	14.24%	-5.39%	39.62%	49.00%	-19.05%	51.82%	32.67%	45.70%	10.60%	22.37%

Correlation

The correlation between TAN and COST is -0.11, meaning they tend to move in opposite directions. This is especially valuable for risk management - when one declines, the other has historically tended to hold steady or rise.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	-0.11
Correlation (3Y) Calculated over the trailing 3-year period	0.05
Correlation (5Y) Calculated over the trailing 5-year period	0.19
Correlation (10Y) Calculated over the trailing 10-year period	0.22
Correlation (All Time) Calculated using the full available price history since Apr 15, 2008	0.26

The correlation between TAN and COST shifts across timeframes, from -0.11 (1 year) to 0.26 (all time), reflecting how their relationship changes across market environments.

Return for Risk

TAN vs. COST — Risk / Return Rank

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

TAN

TAN Risk / Return Rank: 76
TAN Sharpe Ratio Rank: 78
TAN Sortino Ratio Rank: 71
TAN Omega Ratio Rank: 65
TAN Calmar Ratio Rank: 86
TAN Martin Ratio Rank: 81

COST

COST Risk / Return Rank: 37
COST Sharpe Ratio Rank: 40
COST Sortino Ratio Rank: 32
COST Omega Ratio Rank: 32
COST Calmar Ratio Rank: 40
COST Martin Ratio Rank: 39

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.

TAN vs. COST - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Invesco Solar ETF (TAN) and Costco Wholesale Corporation (COST). 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.

	TAN	COST	Difference
Sharpe ratio: Return per unit of total volatility	2.17	-0.08	+2.25
Sortino ratio: Return per unit of downside risk	2.75	0.02	+2.73
Omega ratio: Gain probability vs. loss probability	1.34	1.00	+0.33
Calmar ratio: Return relative to maximum drawdown	4.23	-0.10	+4.33
Martin ratio: Return relative to average drawdown	13.77	-0.22	+13.99

TAN vs. COST - Sharpe Ratio Comparison

The current TAN Sharpe Ratio is 2.17, which is higher than the COST Sharpe Ratio of -0.08. The chart below compares the historical Sharpe Ratios of TAN and COST, 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

TAN vs. COST - Drawdown Comparison

The maximum TAN drawdown since its inception was -95.29%, which is greater than COST's maximum drawdown of -53.39%. Use the drawdown chart below to compare losses from any high point for TAN and COST.

Drawdown Indicators

	TAN	COST	Difference
Max Drawdown Largest peak-to-trough decline	-95.29%	-53.39%	-41.90%
Max Drawdown (1Y) Largest decline over 1 year	-19.98%	-15.14%	-4.84%
Max Drawdown (3Y) Largest decline over 3 years	-64.40%	-20.74%	-43.66%
Max Drawdown (5Y) Largest decline over 5 years	-73.95%	-31.40%	-42.55%
Max Drawdown (10Y) Largest decline over 10 years	-78.53%	-31.40%	-47.13%
Current Drawdown Current decline from peak	-71.05%	-10.23%	-60.82%
Average Drawdown Average peak-to-trough decline	-78.48%	-13.36%	-65.12%
Ulcer Index Depth and duration of drawdowns from previous peaks	6.13%	6.67%	-0.54%

Volatility

TAN vs. COST - Volatility Comparison

Invesco Solar ETF (TAN) has a higher volatility of 16.32% compared to Costco Wholesale Corporation (COST) at 7.44%. This indicates that TAN's price experiences larger fluctuations and is considered to be riskier than COST based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	TAN	COST	Difference
Volatility (1M) Calculated over the trailing 1-month period	16.32%	7.44%	+8.88%
Volatility (6M) Calculated over the trailing 6-month period	28.02%	14.53%	+13.49%
Volatility (1Y) Calculated over the trailing 1-year period	39.00%	18.80%	+20.20%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	40.04%	22.72%	+17.32%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	38.11%	21.95%	+16.16%

Dividends

TAN vs. COST - Dividend Comparison

TAN has not paid dividends to shareholders, while COST's dividend yield for the trailing twelve months is around 0.55%.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
COST Costco Wholesale Corporation	0.55%	0.59%	0.49%	2.87%	0.76%	0.54%	3.38%	0.86%	1.08%	4.81%	1.09%	4.06%
TAN Invesco Solar ETF	0.00%	0.00%	0.50%	0.09%	0.00%	0.00%	0.09%	0.30%	0.69%	1.77%	5.04%	1.60%

Frequently Asked Questions

Can I hold both TAN and COST in my portfolio?

TAN and COST have a correlation of -0.11, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, TAN or COST?

TAN has higher volatility (16.32%) compared to COST (7.44%). In terms of maximum drawdown, TAN dropped -95.29% vs COST's -53.39%.

Which has better risk-adjusted returns?

TAN currently has the higher Sharpe Ratio (2.17 vs -0.08), 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.