Barclays (LSE: BARC) shares have crashed more than 20% since their peak in early February. But investors who bought two years ago hopefully won’t feel too bad about that, seeing as the value of their investment has still more than doubled.

Yes, the Barclays share price is up 110% since the end of March 2024. That means £5,000 invested back then is now worth £10,500. And even the horrific events in the Middle East, with the resulting surge in oil prices, are only enough to take Barclays shareholders back to the price of late October 2025.

As an aside, I see those who managed to buy Barclays shares immediately after the big pandemic crash in early 2020 are now sitting on a five-bagger. That’s enough to turn £5,000 into £25,000 — I know the sums aren’t difficult, but it’s so good it’s worth stating.

Cool heads prevail

I’m not using these dates to suggest we should try to time the market. No, it’s not how most successful investors operate. In fact, for most of us it’s probably more likely to damage our returns. Buying and selling whenever we think we see a bottom or a top costs money in charges. And that’s on top of likely losses through poor timing.

Instead, let’s remember a couple of things long-term Foolish investors know only too well. Investing in quality companies for the long term, while ignoring short-term ups and downs, can be very profitable. And a market downturn can be our friend, not our enemy.

Maybe the first impulse that should come to our mind when we see a favourite stock fall is the famous: “Don’t do something, just stand there.” There’s almost never any need to rush into rapid action. You know, like the knee-jerk sellers back in 2020 who presented us with such a brilliant buying opportunity.

What to do now?

That brings me to today’s big question. Is this latest fall in Barclays shares another buying opportunity? I think it might be. Bank stocks and other financials tend to be among the first casualties of a stock market sell-off. And in my view, they’re some of the best to consider for recovery.

Barclays isn’t such an attractive dividend stock these days. Not with share price rises of the past couple of years pushing the forecast dividend yield down to just 2.2%.

But what does a forward price-to-earnings (P/E) ratio of only 7.3 say to us? And what if it drops as low as 6.2 in 2027 as forecasts suggest? I know forecasts are uncertain at the best of times. And at times of global crisis, they can be up in the air. But I don’t expect significant damage to Barclays’ prospects for the next five years and more.

To me this does look like a good — if unexpected — opportunity to consider buying.