BST vs. CLOA

Last updated Jun 4, 2026

BST (BlackRock Science and Technology Trust) is a stock, while CLOA (BlackRock AAA CLO ETF) is CLO fund actively managed by BlackRock. Over the past 3 years, BST returned 23.83%/yr vs 6.74%/yr for CLOA. At a 0.09 correlation, their price movements are largely independent.

Performance

BST vs. CLOA - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in BlackRock Science and Technology Trust (BST) and BlackRock AAA CLO ETF (CLOA). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, BST achieves a 24.81% return, which is significantly higher than CLOA's 2.06% return.

BST

• 1D: -1.50%
• 1M: 14.60%
• YTD: 24.81%
• 6M: 28.67%
• 1Y: 46.47%
• 3Y*: 23.83%
• 5Y*: 5.46%
• 10Y*: 20.54%

CLOA

• 1D: 0.02%
• 1M: 0.44%
• YTD: 2.06%
• 6M: 2.51%
• 1Y: 5.28%
• 3Y*: 6.74%
• 5Y*: —
• 10Y*: —

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

BST vs. CLOA - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023
BST BlackRock Science and Technology Trust	24.81%	23.65%	17.96%	16.25%
CLOA BlackRock AAA CLO ETF	2.06%	5.44%	7.25%	8.38%

Correlation

The correlation between BST and CLOA is 0.20, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.20
Correlation (3Y) Calculated over the trailing 3-year period	0.10
Correlation (All Time) Calculated using the full available price history since Jan 13, 2023	0.09

The correlation between BST and CLOA shifts across timeframes, from 0.09 (all time) to 0.20 (1 year), reflecting how their relationship changes across market environments.

Return for Risk

BST vs. CLOA — Risk / Return Rank

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

BST

BST Risk / Return Rank: 88
BST Sharpe Ratio Rank: 92
BST Sortino Ratio Rank: 91
BST Omega Ratio Rank: 90
BST Calmar Ratio Rank: 82
BST Martin Ratio Rank: 87

CLOA

CLOA Risk / Return Rank: 99
CLOA Sharpe Ratio Rank: 99
CLOA Sortino Ratio Rank: 99
CLOA Omega Ratio Rank: 99
CLOA Calmar Ratio Rank: 99
CLOA Martin Ratio Rank: 99

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.

BST vs. CLOA - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for BlackRock Science and Technology Trust (BST) and BlackRock AAA CLO ETF (CLOA). 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.

	BST	CLOA	Difference
Sharpe ratio: Return per unit of total volatility	2.59	7.45	-4.87
Sortino ratio: Return per unit of downside risk	3.47	13.98	-10.51
Omega ratio: Gain probability vs. loss probability	1.45	3.34	-1.89
Calmar ratio: Return relative to maximum drawdown	3.05	30.02	-26.97
Martin ratio: Return relative to average drawdown	10.09	150.47	-140.38
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

BST vs. CLOA - Sharpe Ratio Comparison

The current BST Sharpe Ratio is 2.59, which is lower than the CLOA Sharpe Ratio of 7.45. The chart below compares the historical Sharpe Ratios of BST and CLOA, 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

	BST	CLOA	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.59	7.45	-4.87
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.23	—	—
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.80	—	—
Sharpe Ratio (All Time) Calculated using the full available price history	0.66	5.22	-4.56

Drawdowns

BST vs. CLOA - Drawdown Comparison

The maximum BST drawdown since its inception was -47.72%, which is greater than CLOA's maximum drawdown of -1.34%. Use the drawdown chart below to compare losses from any high point for BST and CLOA.

Drawdown Indicators

	BST	CLOA	Difference
Max Drawdown Largest peak-to-trough decline	-47.72%	-1.34%	-46.38%
Max Drawdown (1Y) Largest decline over 1 year	-15.31%	-0.18%	-15.13%
Max Drawdown (3Y) Largest decline over 3 years	-23.37%	-1.13%	-22.24%
Max Drawdown (5Y) Largest decline over 5 years	-47.72%	—	—
Max Drawdown (10Y) Largest decline over 10 years	-47.72%	—	—
Current Drawdown Current decline from peak	-1.50%	0.00%	-1.50%
Average Drawdown Average peak-to-trough decline	-12.98%	-0.05%	-12.93%
Ulcer Index Depth and duration of drawdowns from previous peaks	4.62%	0.04%	+4.58%

Volatility

BST vs. CLOA - Volatility Comparison

BlackRock Science and Technology Trust (BST) has a higher volatility of 6.35% compared to BlackRock AAA CLO ETF (CLOA) at 0.15%. This indicates that BST's price experiences larger fluctuations and is considered to be riskier than CLOA based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	BST	CLOA	Difference
Volatility (1M) Calculated over the trailing 1-month period	6.35%	0.15%	+6.20%
Volatility (6M) Calculated over the trailing 6-month period	15.24%	0.48%	+14.76%
Volatility (1Y) Calculated over the trailing 1-year period	18.07%	0.71%	+17.36%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	23.61%	1.32%	+22.29%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	25.75%	1.32%	+24.43%

Dividends

BST vs. CLOA - Dividend Comparison

BST's dividend yield for the trailing twelve months is around 8.56%, more than CLOA's 4.96% yield.

Position	TTM	2025	2024	2023	2022	2021	2020	2019	2018	2017	2016	2015
BST BlackRock Science and Technology Trust	8.56%	10.36%	8.21%	8.91%	10.57%	5.38%	3.85%	10.52%	6.41%	4.80%	6.69%	6.93%
CLOA BlackRock AAA CLO ETF	4.96%	5.35%	6.01%	5.88%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%

Frequently Asked Questions

Can I hold both BST and CLOA in my portfolio?

BST and CLOA have a correlation of 0.20, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, BST or CLOA?

BST has higher volatility (6.35%) compared to CLOA (0.15%). In terms of maximum drawdown, BST dropped -47.72% vs CLOA's -1.34%.

Which has better risk-adjusted returns?

CLOA currently has the higher Sharpe Ratio (7.45 vs 2.59), 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.