BYBU.L vs. CSPX.L

Last updated Jun 5, 2026

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

Performance

BYBU.L vs. CSPX.L - Performance Comparison

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

Returns By Period

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

BYBU.L

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

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%

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

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

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019	2018	2017
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%
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%

Correlation

The correlation between BYBU.L and CSPX.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, BYBU.L and CSPX.L have become more correlated (0.63) than their long-term average of 0.40, meaning their price movements have been converging.

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

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

Return for Risk

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

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

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

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

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.

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

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

	BYBU.L	CSPX.L	Difference
Sharpe ratio: Return per unit of total volatility	1.90	2.32	-0.42
Sortino ratio: Return per unit of downside risk	2.87	3.41	-0.54
Omega ratio: Gain probability vs. loss probability	1.33	1.42	-0.10
Calmar ratio: Return relative to maximum drawdown	4.34	3.35	+1.00
Martin ratio: Return relative to average drawdown	12.04	14.51	-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.

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

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

	BYBU.L	CSPX.L	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	1.90	2.32	-0.42
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	0.83	0.86	-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	1.14	0.94	+0.20

Drawdowns

BYBU.L vs. CSPX.L - Drawdown Comparison

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

Drawdown Indicators

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

Volatility

BYBU.L vs. CSPX.L - Volatility Comparison

Amundi S&P 500 Buyback ETF-C USD (BYBU.L) has a higher volatility of 3.55% compared to iShares Core S&P 500 UCITS ETF USD (Acc) (CSPX.L) at 3.13%. This indicates that BYBU.L's price experiences larger fluctuations and is considered to be riskier than CSPX.L based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

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

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

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

Dividends

BYBU.L vs. CSPX.L - Dividend Comparison

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

Tickers have no history of dividend payments

Frequently Asked Questions

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

BYBU.L and CSPX.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, BYBU.L or CSPX.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, BYBU.L or CSPX.L?

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

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

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