The market is getting tired and that's a reason to be cautious, said Peter Costa, president of Empire Executions.
"I think we're in a very tired phase. We are reaching new highs, but the highs are only 35 or 40 points above the last close. So to me, that just tells me things are starting run out of steam," Costa, who is also a CNBC contributor, said Friday on "Closing Bell."
Larry Glazer, managing partner at Mayflower Advisors, agreed. He said on "Closing Bell" that with the Dow above 18,000, "there aren't a lot of bargains to be had." The slew of lackluster earnings over the past week are evidence of the difficulties in the market, Glazer said Friday.
The sectors and stocks that are outperforming are the "unloved" sectors, he said.
"The sectors that nobody wanted like banks and biotech are starting to act a little bit better. So I think that's going to be your playbook for the second half of the year and investors should listen to the market and listen to what's happening," he said.
Empire's Costa said that another warning sign is the strength of the dollar.
"It's going to impact a lot of the multinationals' earnings, it's going to make it worse," he said.
Holly Liss, managing director at BTIG, agreed that the U.S. currency could continue to strengthen, adding that Treasury yields could move even lower.
"It's sort of a self-serving prophecy in that the stronger dollar is keeping inflation and price pressures from coming into this country, being imported here or even just from building here, which is also then helping keep pressure on the yields to move even lower," she said Friday on "Closing Bell."