One of the market’s biggest bulls sees stocks getting their groove back this year, but his forecast comes with an expiration date.

According to Blackstone’s Joseph Zidle, there’s evidence that rising inflation will tear into corporate profits and stretch consumers within the next 12 months.

“As we get into 2019, this earnings cycle is going to run its course. The earnings growth will have to slow because the year-over-year comps get so tough,” he told CNBC’s “Futures Now” on Thursday. “When you’ve got slower earnings growth and higher interest rates, that’s going to knock down equity valuations.”

It’s a scenario that’s already unfolding.

“It’s not strong, but it’s broad-based. We’re seeing it in things like higher oil prices and higher gas prices where oil is up 50 percent year over year. Gas is up 20 percent year over year. We’re seeing it all throughout wages,” he said.

Despite his cautious outlook for next year, Zidle believes it’s way too premature for investors to head into the bear camp — saying that the “tug-of-war” between macro headwinds such as North Korea tensions and fundamentals will end favorably for stocks by summer.

“When you’re lifting up the hood on the earnings story, it really tells you they’re quite healthy. So, I think the fundamentals are going to ultimately win out here,” said Zidle. “I’m optimistic. I think the second half is actually going to be a very good environment for equities.”

He has a 3,000 year-end forecast on the S&P 500, about a 10 percent increase from current levels. According to Zidle, energy, materials, industrials and emerging markets will lead the markets back into record territory.

But Zidle pointed out that many investors are sabotaging themselves right now by abandoning overweight positions in stocks in favor of fixed income, an area of the markets often seemed safer when there’s fear of an economic slowdown.

“Investors are overweight fixed income, and they’re intermediate to long-term durations. So, they’re not positioned for that rise in rates,” Zidle said. “They are taking duration risk at a time when they ought to be very short duration and taking credit risk.”