A01
What Is a Stock Market Index?
An index measures a defined group of securities using rules for membership, weighting, and calculation.
Full editorial draft available for owner review; not approved for public indexing.Market Education / Collection
Index Fundamentals
Learn what indexes represent, how they are built, and why the S&P 500, Nasdaq-100, and Dow move differently.
6 topics in this collection · 3 existing full guides · 3 new drafts
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A02
How Is the S&P 500 Calculated?
The S&P 500 uses float-adjusted market capitalization and an index divisor to measure the large-cap U.S. equity market.
A03
How Is the Nasdaq-100 Weighted?
The Nasdaq-100 uses modified market-cap weighting, with methodology rules that shape membership and constituent influence.
A04
Why Is the Dow Price-Weighted?
The Dow divides the sum of its constituent share prices by a divisor; it is price-weighted rather than market-cap-weighted.
A05
S&P 500 vs. Nasdaq-100 vs. Dow 30
Compare membership, weighting methods, and what each index can and cannot represent.
Full editorial draft available for owner review; not approved for public indexing.A06
What Are SPX, NDX, DJIA, ES, NQ, and YM?
Distinguish cash indexes from futures contracts that reference related benchmarks.
Full editorial draft available for owner review; not approved for public indexing.