The Barclays (LSE: BARC) share price has had a brilliant run. Until now. It plunged 10.75% last week and is down 15.6% over the month. Have I just been handed a brilliant opportunity to fill my boots?

Lately, FTSE 100 banks have been flying across the board. Happily, I haven’t missed out altogether. I bought Lloyds shares in 2023, and I’m sitting on a total return of 150%, even after the recent dip. I’m thrilled to have got in at a decent valuation, with the price-to-earnings ratio only around five or six at the time.

I’ve been desperate to broaden my exposure to the big banks, which have finally shaken off the trauma of the financial crisis and now look in much better shape.

FTSE 100 opportunity

Barclays is right at the top of my list. One thing has stopped me, though: the shares have just done almost too well. Last month they looked fully valued, with the P/E nudging towards 15. I’m always wary of buying into a stock or sector after a strong run, in case I park my cash just before the wheels come off.

And now they have. Although the dip is far from catastrophic: the Barclays share price is still up 31% over 12 months and 135% over 10 years. But I’m sensing my moment is here.

The recent fall isn’t all about Iran. Barclays is actually falling twice as fast as the FTSE 100, which ended last week 5.74% lower. And the decline started even before the US attacks. On 10 February, the bank issued what I thought was a bumper set of full-year 2025 figures. Profits jumped 13% to £9.1bn, the board unveiled a new £1bn share buyback, and announced plans to return £15bn to investors over the next two years.

I’m ready to buy this stock

Earnings met high investor expectations, but didn’t beat them. The shares retreated. Then the Iran crisis hit, and they fell further. Result? The P/E is down to around 9.5, and the price-to-book ratio has retreated to 0.9. Both scream value for such a profitable and well-managed enterprise, in my view.

The dividend has crept up to 2.1% on a trailing basis. That’s low for the sector, but mainly because Barclays plans to reward shareholders more via buybacks. Personally, I prefer dividends. But it’s far from a dealbreaker. Of course, there are risks. JP Morgan chief Jamie Dimon warns the banking sector is exposed to bad loans amid the AI boom. Barclays has global exposure, which makes it riskier than UK-focused Lloyds, but potentially more rewarding. If the stock market falls further next week, recent evidence suggests that Barclays could fall faster.

With a long-term view, I think it looks worth considering today. If tensions persist and the shares get even cheaper, I’ll personally find it even more tempting. But I’ve learned the hard way that trying to catch the absolute bottom of the market is impossible. Instead, I’ll start by drip feeding money in.

On The Motley Fool, we’re strictly banned from buying or selling shares for two full trading days after we write about them. When that period ends, my finger will be hovering over the Buy button. And there’s a few other falling FTSE 100 stocks I’m itching to purchase today.