Can Data Reveal a Cartel? | The Nasdaq Missing Eighths

Opublikowano: 2026-09-22

In the early 1990s, Nasdaq stocks were quoted in eighths of a dollar. $20.00, $20.125, $20.25, $20.375, etc. But economists William Christie and Paul Schultz found an odd pattern. For many actively traded stocks, market makers mostly used even eighths. Instead, prices acted as if quotes were changing in quarter-dollar increments. Why? Because? The empirical evidence alone cannot prove that dealers agreed to keep spreads wider. But once the research was released, odd-eighth quotes started to show up, and spreads tightened considerably. Then government investigators dug deeper, finding evidence that went far beyond the original...