FTEK vs. TAN

Last updated Jun 3, 2026

FTEK (Fuel Tech, Inc.) is a stock, while TAN (Invesco Solar ETF) is Alternative Energy Equities fund tracking the MAC Global Solar Energy Index. Over the past 10 years, FTEK returned -0.66%/yr vs 13.81%/yr for TAN. At a 0.27 correlation, their price movements are largely independent.

Performance

FTEK vs. TAN - Performance Comparison

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

Returns By Period

In the year-to-date period, FTEK achieves a -5.77% return, which is significantly lower than TAN's 47.13% return. Over the past 10 years, FTEK has underperformed TAN with an annualized return of -0.66%, while TAN has yielded a comparatively higher 13.81% annualized return.

FTEK

• 1D: -0.68%
• 1M: -8.70%
• YTD: -5.77%
• 6M: -16.95%
• 1Y: -8.12%
• 3Y*: 2.63%
• 5Y*: -7.32%
• 10Y*: -0.66%

TAN

• 1D: 1.60%
• 1M: 21.93%
• YTD: 47.13%
• 6M: 51.73%
• 1Y: 127.12%
• 3Y*: 0.29%
• 5Y*: -0.77%
• 10Y*: 13.81%

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

FTEK vs. TAN - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
FTEK Fuel Tech, Inc.	-5.77%	48.57%	0.00%	-17.65%	-8.93%	-63.92%	308.42%	-20.17%	6.25%	-2.61%
TAN Invesco Solar ETF	47.13%	48.31%	-37.61%	-26.79%	-5.24%	-25.10%	233.96%	66.53%	-25.67%	54.38%

Correlation

The correlation between FTEK and TAN is 0.13, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.13
Correlation (3Y) Calculated over the trailing 3-year period	0.12
Correlation (5Y) Calculated over the trailing 5-year period	0.25
Correlation (10Y) Calculated over the trailing 10-year period	0.21
Correlation (All Time) Calculated using the full available price history since Apr 16, 2008	0.27

The correlation between FTEK and TAN shifts across timeframes, from 0.12 (3 years) to 0.27 (all time), reflecting how their relationship changes across market environments.

Return for Risk

FTEK vs. TAN — Risk / Return Rank

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

FTEK

FTEK Risk / Return Rank: 36
FTEK Sharpe Ratio Rank: 36
FTEK Sortino Ratio Rank: 38
FTEK Omega Ratio Rank: 37
FTEK Calmar Ratio Rank: 35
FTEK Martin Ratio Rank: 36

TAN

TAN Risk / Return Rank: 89
TAN Sharpe Ratio Rank: 93
TAN Sortino Ratio Rank: 87
TAN Omega Ratio Rank: 80
TAN Calmar Ratio Rank: 96
TAN Martin Ratio Rank: 91

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.

FTEK vs. TAN - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Fuel Tech, Inc. (FTEK) and Invesco Solar ETF (TAN). 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.

	FTEK	TAN	Difference
Sharpe ratio Return per unit of total volatility	-0.11	3.44	-3.55
Sortino ratio Return per unit of downside risk	0.38	3.94	-3.56
Omega ratio Gain probability vs. loss probability	1.04	1.48	-0.44
Calmar ratio Return relative to maximum drawdown	-0.17	9.06	-9.23
Martin ratio Return relative to average drawdown	-0.25	22.01	-22.26
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

FTEK vs. TAN - Sharpe Ratio Comparison

The current FTEK Sharpe Ratio is -0.11, which is lower than the TAN Sharpe Ratio of 3.44. The chart below compares the historical Sharpe Ratios of FTEK and TAN, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Sharpe Ratios by Period

	FTEK	TAN	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	-0.11	3.44	-3.55
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	-0.12	-0.02	-0.10
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	-0.01	0.37	-0.37
Sharpe Ratio (All Time) Calculated using the full available price history	-0.06	-0.12	+0.06

Drawdowns

FTEK vs. TAN - Drawdown Comparison

The maximum FTEK drawdown since its inception was -98.97%, roughly equal to the maximum TAN drawdown of -95.29%. Use the drawdown chart below to compare losses from any high point for FTEK and TAN.

Drawdown Indicators

	FTEK	TAN	Difference
Max Drawdown Largest peak-to-trough decline	-98.97%	-95.29%	-3.68%
Max Drawdown (1Y) Largest decline over 1 year	-67.22%	-13.62%	-53.60%
Max Drawdown (3Y) Largest decline over 3 years	-67.22%	-64.40%	-2.82%
Max Drawdown (5Y) Largest decline over 5 years	-68.77%	-73.95%	+5.18%
Max Drawdown (10Y) Largest decline over 10 years	-86.07%	-78.53%	-7.54%
Current Drawdown Current decline from peak	-96.12%	-66.81%	-29.31%
Average Drawdown Average peak-to-trough decline	-78.47%	-78.51%	+0.04%
Ulcer Index Depth and duration of drawdowns from previous peaks	45.13%	5.61%	+39.52%

Volatility

FTEK vs. TAN - Volatility Comparison

Fuel Tech, Inc. (FTEK) has a higher volatility of 19.08% compared to Invesco Solar ETF (TAN) at 11.81%. This indicates that FTEK's price experiences larger fluctuations and is considered to be riskier than TAN based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	FTEK	TAN	Difference
Volatility (1M) Calculated over the trailing 1-month period	19.08%	11.81%	+7.27%
Volatility (6M) Calculated over the trailing 6-month period	45.02%	25.30%	+19.72%
Volatility (1Y) Calculated over the trailing 1-year period	73.54%	37.21%	+36.33%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	60.78%	39.74%	+21.04%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	94.73%	37.98%	+56.75%

Dividends

FTEK vs. TAN - Dividend Comparison

Neither FTEK nor TAN has paid dividends to shareholders.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
FTEK Fuel Tech, Inc.	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%
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 FTEK and TAN in my portfolio?

FTEK and TAN have a correlation of 0.13, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, FTEK or TAN?

FTEK has higher volatility (19.08%) compared to TAN (11.81%). In terms of maximum drawdown, FTEK dropped -98.97% vs TAN's -95.29%.

Which has better risk-adjusted returns?

TAN currently has the higher Sharpe Ratio (3.44 vs -0.11), 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.