One year ago, almost every major broker declared Commonwealth Bank of Australia (ASX: CBA) shares as overvalued and destined to crash deep into the red.

They were urging investors to stay away and focus on other areas of the market.

These recommendations were arguably justifiable given the multiples that its shares were trading on. For example, numerous times it was highlighted that CBA was the most expensive bank share in the world.

But much to the delight of investors that were brave enough to invest in Australia's largest bank a year ago, CBA and the rest of the big four banks did not crash deep into the red. Far from it!

During this time, the banking giants have defied the odds and outperformed the market by some distance, helping underpin the impressive 20% gain by the S&P/ASX 200 Index (ASX: XJO) over the 12 months.

And don't worry if you didn't buy CBA and other ASX bank shares a year ago, you are likely to have benefitted indirectly through your super fund. Most major super funds own a slice of the big four banks.

But what about if I did buy the banking giant's shares a year ago? What about if I put $5,000 into its shares? Let's see what that would be worth now.

$5,000 invested in CBA shares a year ago

One year ago, I could have invested in CBA at a price of $104.71.

This means that a $5,000 investment (plus an extra $26.08) would have left me owning 48 shares in Australian leading bank.

On Wednesday, CBA shares were changing hands for a lofty $156.93 at the market close.

This means that if I were to have sold those 48 shares at the close, I would have received a cool $7,532.64 for them.

That's a return of $2,506.56 or approximately 50% on my original investment from one year ago.

This is a staggering return and something you may expect from a growth share like Pro Medicus Limited (ASX: PME) or Xero Ltd (ASX: XRO), but certainly not from a banking behemoth.

But wait, there's more! Unlike Pro Medicus and Xero, CBA rewards its shareholders with dividends every six months.

This saw the bank pay out a total of $4.65 per share to shareholders over the 12 months. This means that those 48 units would have pulled in $223.20 in dividend income, boosting the total return to $2,729.76 from an investment of just over $5,000.

Here's hoping 2025 will be successful. Though, surely it can't be as successful, right?