Glossary term

American Stock Exchange

The American Stock Exchange was a U.S. securities exchange that became part of NYSE and is now associated with NYSE American.

Updated

May 21, 2026

Read time

2 min read

What Was the American Stock Exchange?

The American Stock Exchange, often called AMEX, was a U.S. securities exchange with roots in New York's curb market. It became known for trading smaller-company stocks, options, exchange-traded products, and securities that did not necessarily fit the New York Stock Exchange's traditional listing profile.

In 2008, NYSE Euronext acquired the American Stock Exchange. The modern successor is associated with NYSE American, a NYSE market focused on smaller and growth-oriented companies.

Key Takeaways

  • The American Stock Exchange was a major U.S. securities exchange.
  • It grew out of New York's historic curb market.
  • It was acquired by NYSE Euronext in 2008.
  • NYSE American is the modern exchange lineage most closely tied to AMEX.
  • The term matters when reading older filings, ticker histories, and exchange references.

How AMEX Fit the Market

AMEX historically offered a venue for companies and products that were different from the largest NYSE-listed blue chips. It became important for options and exchange-traded products, and it provided a public market for many smaller companies.

That role gave investors access to a broader set of securities, but smaller listings often came with greater liquidity, disclosure, and business-model risk.

Transition to NYSE American

After the 2008 acquisition, the AMEX name changed through several phases, including NYSE Amex and NYSE MKT, before becoming NYSE American. The modern NYSE American market is part of the NYSE exchange group.

This history matters because old references to AMEX may refer to securities, rules, exchange memberships, or price histories that now sit under a different exchange name.

Investor Context

Exchange venue can affect listing standards, liquidity, market structure, fees, auction rules, and trading mechanics. It does not by itself determine investment quality. A company listed on a smaller-company market can be attractive or risky depending on its fundamentals, governance, liquidity, and valuation.

When researching older securities, investors should confirm whether the company still trades, moved to another exchange, changed ticker, merged, delisted, or became part of a successor market.

AMEX Versus NYSE

Exchange reference

Historical role

Current reading

American Stock Exchange

Historic exchange and curb-market successor

Legacy name in older documents

NYSE American

Modern NYSE market lineage

Current exchange venue for smaller and growth companies

The Bottom Line

The American Stock Exchange is now mainly a historical and legacy-market reference. Its importance is in understanding how smaller-company and options markets developed, and how older AMEX references connect to today's NYSE American structure.

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