A striking streak in the S&P 500 Index has Ryan Detrick of LPL Financial calling for a market slip.

As of Thursday, it had been exactly 10 months since the S&P 500 saw a pullback of 3 percent, Detrick pointed out. That makes this only the second-longest streak without a 3 percent pullback that has been since 1928, beaten by an 11-month run that took place from the end of 1994 to December 1995.

That extended rally suggests stocks may be overdue for a downturn. Looking forward, Detrick concludes that the market is long overdue for shallow pullback.

"Could we keep going higher without a lot of volatility? It's possible, but we just think it's been awfully long so that a normal correction this time of the year makes a lot of sense to us here," the market strategist said last week on CNBC's "Futures Now."

At the same time, Detrick says that investors shouldn't react too nervously once that long-awaited drop takes place.

"It's just important to remember that whatever the reason may be when that inevitable correction happens, [investors should not] panic," he said. "The economy still looks good, and potentially, this bull market still has a long way to go. It's just near-term, things look dicey."

Markets were mixed on Friday, with the Dow being the only major average that moved higher for the day.