Choose the sector universe before ranking it
This example uses the 11 equity Select Sector SPDR ETFs listed by State Street. They represent sectors of the S&P 500, so the experiment concerns US large-cap sector exposure. It does not cover the whole global equity market, every industry or every sector fund. SPY is a benchmark and market filter, not a candidate for either sector slot.
- Freeze ticker identifiers, exchanges, currency, session and data provider with the research record. Do not replace a poorly performing fund after seeing its returns.
- State Street lists inception dates of June 18, 2018 for XLC and October 7, 2015 for XLRE. Start this fixed-universe test only after every fund has the required observations. Never treat pre-inception prices as tradable ETF history.
- A historical index proxy or a changing universe is a separate experiment. Record when each instrument became eligible, any closures and sector classification changes. Choosing only funds surviving today leaves selection bias even when the price series are clean.
| ETF | Sector |
|---|---|
| XLB | Materials |
| XLC | Communication services |
| XLE | Energy |
| XLF | Financials |
| XLI | Industrials |
| XLK | Technology |
| XLP | Consumer staples |
| XLRE | Real estate |
| XLU | Utilities |
| XLV | Health care |
| XLY | Consumer discretionary |