Wells Fargo Securities' Christopher Harvey is looking for a signal that it's time to take risk off the table, and he expects it'll come sooner rather than later.
The firm's head of equity strategy is worried market sentiment is becoming too optimistic as stocks trade near all-time highs.
"We kinda hate this market," Harvey told CNBC's "Trading Nation" on Wednesday. "When did we stop liking this market? It's been relatively recent. The market has moved very close to our price target, and many of the catalysts that we talked about have played out."
Those drivers included Federal Reserve interest rate policy, better-than-expected earnings and too much bearishness among investors.
Harvey's 2019 year-end S&P 500 price target is 3,088. As of Wednesday's close, the index is less than 1% away from that.
"What we're left with is near-term sentiment and near-term sentiment being the driver of prices," he said. "That could be based on a tweet. It could be based on positioning. And so, it becomes very difficult to handicap this market at this point in time."
Despite his cautiousness, Harvey is not forecasting a dramatic plunge.
"We don't think the wheels are going to fall off the cart," he said. "We don't think we're going to have a 10% correction."
He expects a return to a less exciting stock market environment that supports much smaller returns starting as early as next year.
"I would say mid single digits for your capital market returns. And, if you have mid single digits, you should be happy," added Harvey. "These double-digit returns that we're used to? I think those are a thing of the past."
Harvey is in the process of determining the level he'd start taking profits. He believes the market isn't there yet, but it's getting closer.
"Do we talk about a melt-up? Is that possible? Sure, that's possible," Harvey said. "As we look forward, there's not much left for us to substantially say the market is going to move higher."