As mentioned in the original post, since 2009, this was the Nasdaq's 9th instance of an 8 day or longer winning streak. The index's short and intermediate-term performance after those streaks suggested that we were likely to see some immediate weakness (5, 10, 20 days out) followed by very mild gains further out (50 days). Much weaker performance than if you just bought the index on any given day during this 6 year bull.
As we study the results of this most recent streak, we see a bit more dispersion but the general theme has remained: weak to flat action over the next several days and weeks.
-Day 20 (March 24th) - Nasdaq closed at 4,994.73 for a gain of 0.53%
-Day 30 (April 8th) - Nasdaq closed at 4,950.82 for a loss of -0.35%
While the Nasdaq's lack of returns over these time periods can't be attributed to the predictive powers to this or any other study, it's interesting to know that after the index goes on such runs of momentum it's common for it to take a breather for a few weeks/months. And that's indeed what it's done here.