US experience with futures transaction taxes

The transaction tax on futures reduced trading volume during the 1920s and 1930s but had no apparent effect on volatility or open interest. The relative magnitude of the tax was highest for intermediaries and appears to have substantially reduced intra‐day trading, but it did not dramatically affect hedging activity or the level of cash or futures prices. Pit traders were particularly distressed by a 400% increase in the tax rate in 1932 and effectively widened spreads by avoiding trades at the minimum price increment. This doubling of the minimum tick size was formally implemented in exchange rules 1 year later.