CSPX.L vs. BYBU.L

Last updated Jun 5, 2026

CSPX.L (iShares Core S&P 500 UCITS ETF USD (Acc)) and BYBU.L (Amundi S&P 500 Buyback ETF-C USD) are both S&P 500 funds - CSPX.L tracks the S&P 500 Index while BYBU.L tracks the S&P 500 Buyback NTR. Both are passively managed. Over the past 5 years, CSPX.L returned 13.72%/yr vs 10.16%/yr for BYBU.L. At a 0.40 correlation, their price movements are largely independent. CSPX.L charges 0.07%/yr vs 0.15%/yr for BYBU.L.

Performance

CSPX.L vs. BYBU.L - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in iShares Core S&P 500 UCITS ETF USD (Acc) (CSPX.L) and Amundi S&P 500 Buyback ETF-C USD (BYBU.L). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, CSPX.L achieves a 10.32% return, which is significantly higher than BYBU.L's 8.18% return.

CSPX.L

• 1D: 0.01%
• 1M: 4.51%
• YTD: 10.32%
• 6M: 11.15%
• 1Y: 27.85%
• 3Y*: 22.17%
• 5Y*: 13.72%
• 10Y*: 15.22%

BYBU.L

• 1D: 0.96%
• 1M: 4.76%
• YTD: 8.18%
• 6M: 9.93%
• 1Y: 22.65%
• 3Y*: 18.64%
• 5Y*: 10.16%
• 10Y*: —

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

CSPX.L vs. BYBU.L - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
CSPX.L iShares Core S&P 500 UCITS ETF USD (Acc)	10.32%	17.45%	25.25%	26.74%	-18.72%	29.35%	17.62%	30.55%	-5.46%	9.45%
BYBU.L Amundi S&P 500 Buyback ETF-C USD	8.18%	17.38%	14.97%	15.90%	-12.83%	37.69%	3.27%	31.62%	-6.60%	8.16%

Correlation

The correlation between CSPX.L and BYBU.L is 0.63, which is moderate. They share some common price drivers but move independently often enough to provide real diversification benefit when combined.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.63
Correlation (3Y) Calculated over the trailing 3-year period	0.47
Correlation (5Y) Calculated over the trailing 5-year period	0.49
Correlation (All Time) Calculated using the full available price history since Jul 28, 2017	0.40

Over the past year, CSPX.L and BYBU.L have become more correlated (0.63) than their long-term average of 0.40, meaning their price movements have been converging.

CSPX.L vs. BYBU.L - Sectors Allocation Comparison

Sectors	CSPX.L	BYBU.L
Technology	38.2%	22.4%
Financial Services	11.1%	27.9%
Communication Services	10.9%	4.6%
Consumer Cyclical	10.0%	15.8%
Healthcare	8.3%	7.5%
Industrials	7.9%	9.0%
Consumer Defensive	4.7%	3.7%
Energy	3.2%	5.2%
Utilities	2.2%	0.9%
Real Estate	1.9%	3.0%
Basic Materials	1.7%	3.1%

Return for Risk

CSPX.L vs. BYBU.L — Risk / Return Rank

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

CSPX.L

CSPX.L Risk / Return Rank: 73
CSPX.L Sharpe Ratio Rank: 72
CSPX.L Sortino Ratio Rank: 77
CSPX.L Omega Ratio Rank: 72
CSPX.L Calmar Ratio Rank: 68
CSPX.L Martin Ratio Rank: 77

BYBU.L

BYBU.L Risk / Return Rank: 65
BYBU.L Sharpe Ratio Rank: 57
BYBU.L Sortino Ratio Rank: 62
BYBU.L Omega Ratio Rank: 54
BYBU.L Calmar Ratio Rank: 83
BYBU.L Martin Ratio Rank: 67

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.

CSPX.L vs. BYBU.L - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for iShares Core S&P 500 UCITS ETF USD (Acc) (CSPX.L) and Amundi S&P 500 Buyback ETF-C USD (BYBU.L). 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.

	CSPX.L	BYBU.L	Difference
Sharpe ratio: Return per unit of total volatility	2.32	1.90	+0.42
Sortino ratio: Return per unit of downside risk	3.41	2.87	+0.54
Omega ratio: Gain probability vs. loss probability	1.42	1.33	+0.10
Calmar ratio: Return relative to maximum drawdown	3.35	4.34	-1.00
Martin ratio: Return relative to average drawdown	14.51	12.04	+2.47
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

CSPX.L vs. BYBU.L - Sharpe Ratio Comparison

The current CSPX.L Sharpe Ratio is 2.32, which is comparable to the BYBU.L Sharpe Ratio of 1.90. The chart below compares the historical Sharpe Ratios of CSPX.L and BYBU.L, 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

	CSPX.L	BYBU.L	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	2.32	1.90	+0.42
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.86	0.83	+0.03
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	0.94	—	—
Sharpe Ratio (All Time) Calculated using the full available price history	0.94	1.14	-0.20

Drawdowns

CSPX.L vs. BYBU.L - Drawdown Comparison

The maximum CSPX.L drawdown since its inception was -33.90%, which is greater than BYBU.L's maximum drawdown of -28.64%. Use the drawdown chart below to compare losses from any high point for CSPX.L and BYBU.L.

Drawdown Indicators

	CSPX.L	BYBU.L	Difference
Max Drawdown Largest peak-to-trough decline	-33.90%	-28.64%	-5.26%
Max Drawdown (1Y) Largest decline over 1 year	-8.17%	-5.19%	-2.98%
Max Drawdown (3Y) Largest decline over 3 years	-18.50%	-19.21%	+0.71%
Max Drawdown (5Y) Largest decline over 5 years	-24.39%	-22.11%	-2.28%
Max Drawdown (10Y) Largest decline over 10 years	-33.90%	—	—
Current Drawdown Current decline from peak	-0.53%	0.00%	-0.53%
Average Drawdown Average peak-to-trough decline	-3.72%	-4.86%	+1.14%
Ulcer Index Depth and duration of drawdowns from previous peaks	1.90%	1.88%	+0.02%

Volatility

CSPX.L vs. BYBU.L - Volatility Comparison

The current volatility for iShares Core S&P 500 UCITS ETF USD (Acc) (CSPX.L) is 3.13%, while Amundi S&P 500 Buyback ETF-C USD (BYBU.L) has a volatility of 3.55%. This indicates that CSPX.L experiences smaller price fluctuations and is considered to be less risky than BYBU.L based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	CSPX.L	BYBU.L	Difference
Volatility (1M) Calculated over the trailing 1-month period	3.13%	3.55%	-0.42%
Volatility (6M) Calculated over the trailing 6-month period	8.70%	8.14%	+0.56%
Volatility (1Y) Calculated over the trailing 1-year period	11.80%	11.86%	-0.06%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	15.97%	21.25%	-5.28%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	16.19%	27.74%	-11.55%

CSPX.L vs. BYBU.L - Expense Ratio Comparison

CSPX.L has a 0.07% expense ratio, which is lower than BYBU.L's 0.15% expense ratio. Despite the difference, both funds are considered low-cost compared to the broader market, where average expense ratios usually range from 0.3% to 0.9%.

Dividends

CSPX.L vs. BYBU.L - Dividend Comparison

Neither CSPX.L nor BYBU.L has paid dividends to shareholders.

Tickers have no history of dividend payments

Frequently Asked Questions

Can I hold both CSPX.L and BYBU.L in my portfolio?

CSPX.L and BYBU.L have a correlation of 0.63, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which ETF is better, CSPX.L or BYBU.L?

On fees, CSPX.L is cheaper at 0.07% per year. The better choice depends on whether you care most about return, fees, risk, or income.

Which ETF is cheaper, CSPX.L or BYBU.L?

CSPX.L is cheaper with a 0.07% expense ratio, compared with 0.15% for BYBU.L.

What is the main difference between CSPX.L and BYBU.L?

CSPX.L tracks S&P 500 Index, while BYBU.L tracks S&P 500 Buyback NTR. They also come from different issuers: BlackRock and Amundi. Their fees differ too: 0.07% for CSPX.L and 0.15% for BYBU.L.