Financials may be lagging, but here’s why one strategist believes a turnaround is in sight

Financial stocks post longest losing streak in seven months

Worries about tax reform and a flattening yield curve have hammered shares of financials in the past week, but the sell-off has some market watchers sensing opportunity.

"They're going to prosper because of two things," said ACG Analytics strategist Larry McDonald on Thursday's "Trading Nation." "Growth and deregulation."

McDonald reasons that tax cuts will eventually be passed, and when they are, higher interest rates should follow, which should help the banks.

Financials generally perform better when the difference between short- and long-term rates is big. Currently that difference, called the yield curve, is the narrowest it has been in 10 years.

But McDonald feels that has already been priced into bank shares. "The bottom line is the banks are pricing in a flat curve, which has already happened, he said. "Going forward they'll benefit from a steepening curve."

On the other hand Dennis Davitt, portfolio manager at Harvest Volatility Management, is still wary on the banks. He sees a combination of regulations and foreign demand for debt holding long-term rates lower, which would in theory crimp bank margins.

"The regulations around the long end of the curve, forcing banks to hold those bonds, and the demand for longer-dated bonds out of European banks is going to continue to hold the long end of the curve down," he said on "Trading Nation." "[That's regardless] of what the economy does, regardless of what the Fed does on the front end."

Banks were down slightly Friday and have fallen more than 2 percent for the week, according to the XLF financials-tracking ETF.