Market crush in 1929 was in form of ABC correction (on DJI chart) with
- wave A correcting 50% of the peak price very sharply (within 2 months)
- wave B correcting about 50% of A (within 5 months)
- wave C equals to 1.2 extension of A, but it is 86% price drop from the peak of wave B (within 2 years)