The NASDAQ Composite ended last week in the green.
That makes it nine straight weeks that the index has been up.
Since 1980, there have been nine other 9-week winning streaks, according to a CNBC analysis using Kensho.
Historically, the index is mixed in the next week following these streaks.
But it's up strongly again one full month later.
By then, it has gained an average of an additional 3.5%, trading higher nearly 80% of the time.