# Index proxy

Canonical page: https://synoptiv.com/glossary/index-proxy

A well-known ETF used to represent an index.

Also known as: Tracking ETF, Bellwether ETF

## Definition

An index proxy is a widely held ETF that tracks a benchmark closely enough to stand in for it — for example QQQ for the Nasdaq-100 or SPY for the S&P 500. Official index weights are proprietary, so the tracking ETF’s weights are used in their place.

## Related terms

- [52-week high](https://synoptiv.com/glossary/52-week-high)
- [52-week low](https://synoptiv.com/glossary/52-week-low)
- [AI-written analysis](https://synoptiv.com/glossary/ai-analysis)
- [Analysis as-of price](https://synoptiv.com/glossary/analysis-as-of-price)
- [Analysis version](https://synoptiv.com/glossary/analysis-version)
- [Analyst consensus](https://synoptiv.com/glossary/analyst-consensus)
- [ATR](https://synoptiv.com/glossary/atr)
- [Attention](https://synoptiv.com/glossary/attention)

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