INVESTOR: Wall Street banks will never be as profitable as they once were

Investing in banks used to be a wild ride.

They would make billions of dollars when times were good, and then lose just as much when the market tanked.

Nowadays they're pretty dull.

They take less risk - and look more like utilities than the levered-up, proprietary trading, subprime lending banks of old.

And according to OppenheimerFunds chief investment officer Krishna Memani, that may mean the banks will never get back to the level of profitability they once attained. His firm manages more than $220 billion.

The KBW Nasdaq Bank Index, at the bottom of this post, shows how bank stocks have performed over the past decade.

The index hit a low in March 2009, and has since rebounded. It closed last week at 70, on a par with where it was early 2014.

Memani said the banks could become value traps - companies that look like bargains but never appreciate, often because the sector as a whole is in a difficult spot.

Here's what Memani told Business Insider:

I think financial institutions from a valuation standpoint look very attractive, but the risk with them is that they may end up as being value traps. That is, they will never get to the level of profitability because their leverage is going to be lower and the underlying economic environment that supported that valuation earlier is just never going to come back in the near future.