S&P/ASX 200 Index (ASX: XJO) bank stock Bendigo and Adelaide Bank Ltd (ASX: BEN) is falling hard today.

Bendigo Bank shares closed Friday trading at $13.42. In morning trade on Monday, shares are changing hands for $11.12 apiece, down 17.14%.

For some context, the ASX 200 is down 0.75% at this same time.

This follows Bendigo Bank's half-year results for the six months to 31 December (1H FY 2025).

Here's what's been happening.

ASX 200 bank stock pummelled on results

The Bendigo Bank share price is taking a beating after the ASX 200 bank stock reported a 1.1% year-on-year decline in cash earnings after tax of $265.2 million. Investors will also have noted this is down 9.7% from the previous half-year, and it comes in below consensus expectations.

Profits also took a steep hit, with statutory net profit after tax (NPAT) of $216.8 million, down 23.2% from 1H FY 2024 and down 17.5% from the previous six-month period.

Profits were impacted by higher expenses as the regional bank continued to invest in its transformation program with an eye on long-term growth.

Operating expenses were up 5%, driven by increased investment spend and technology inflationary pressures.

As for Bendigo's net interest margin (NIM) of 1.88%, while this was up 0.05% year on year, it was down 0.06% from the previous six-month period.

At 11.17%, the bank's common equity tier 1 (CET1) ratio also declined by 0.6% year on year and by 0.15% from the prior half. The board noted this remains "well above" its approved target.

On the plus side of the ledger, the ASX 200 bank's residential lending was up 8.5% year on year to $65.2 billion. That's also up 5.3% from the previous half. And customer deposits of $72.0 billion were up 5.3% from 1H FY 2024.

And Bendigo still came through for passive income investors, declaring a fully franked interim dividend of 30 cents per share, in line with the prior interim dividend. Bendigo Bank stock currently trades on a fully franked dividend yield (part trailing, part pending) of around 5.8%.

What did management say?

Commenting on the results pressuring the ASX 200 bank stock today, Bendigo Bank CEO Richard Fennell said:

We have experienced significantly increased demand for both lending and deposit products from our customers, which has led to the strongest balance sheet growth we have experienced in some years. However, our earnings have been challenged both on the income and expense lines.

Fennell noted that the bank has now exceeded $100 billion in assets.

And he said Bendigo is "nearing the final stages" of its six-year transformation program.

What's next for the ASX 200 bank stock?

As for what could impact the ASX 200 bank stock in the months ahead, Bendigo didn't provide specific guidance.

But Fennell noted that, "Australia remains in a strong position and is well-placed to withstand periods of uncertainty or volatility."

He said, "Despite ongoing cost-of-living challenges facing Australian households, we have seen our home loan customers increase their repayments over the half, with 42% now one year ahead on repayments and 86% maintaining a financial buffer."

Fennell added:

We are committed to completing the final phase of our transformation program which will see us operating one core banking system by the end of 2025. The investments we are making will sustain momentum.

With today's big intraday fall factored in, shares in the ASX 200 bank stock remain up by around 12% since this time last year, not including dividends.