Looking back at the 1990s, even in the best bull markets often exhibit seven week to thirteen week corrections.  And these above showed up every nine months early in the rally in 1996 and 1997. Then after six months as the rally extended into 1998.

Once the 1998 bear market was in, the market rallied for nine months before the next seven week correction.  In 2000 the seven week corrections showed up in rapid succession.