The S&P/ASX 200 Index (ASX: XJO) has enjoyed steady gains over the past month, up 3.09% since 1 May. Some of the increase can be attributed to steady share price gains from two of the Big 4 banks.

The other two have suffered a drop in share price over the same period.

The National Australia Bank Ltd (ASX: NAB) share price opened at $37.34 this morning. The share price is up 3.72% over the course of May and up 10.97% over the year.

The Commonwealth Bank of Australia (ASX: CBA) share price opened at $173.79 this morning. The share price is up 3.91% since 1 May and up 46.86% over the year.

The Westpac Banking Corp (ASX: WBC) share price opened at $31.47 this morning. The share price fell sharply from 2 May to 8 May before recovering and remaining stable. Overall, Westpac's share price is down 4.11% over the month, but is still up 20.99% over the year.

The ANZ Group Holdings Ltd (ASX: ANZ) share price opened at $28.91 this morning. The share price has fallen 2.79% throughout May, but is up 3.73% over the year.

Big 4 bank price targets

In a note to investors yesterday, Macquarie Group Ltd (ASX: MQG) revealed its price targets on Australia's big 4 banks.

NAB shares have been given a neutral rating and a price target of $35. This would represent a 6.26% drop from today's share price.

Macquarie has maintained its underperform rating on CBA shares, revealing a $105 price target. This would represent a significant drop of 39.58% from today's share price.

It kept its underperform rating on Westpac shares and issued a $27.50 price target. The broker clearly thinks there is more room for decline, as this would represent a 12.61% drop from today's share price.

The broker has placed a neutral rating and a $27.50 price target on ANZ shares. This would represent a 4.87% drop from today's share price.

The new price targets follow Macquarie's update to its New Zealand margin analysis for rate cuts, term deposit headwinds, mortgage tailwinds, and the replicating portfolio.

"We make minor EPS [earnings per share] upgrades to (<1%) in FY25E-27E to ANZ, CBA, and WBC, while making minor downgrades to NAB," Macquarie's note said.

What is on the horizon for the big 4 banks?

In NAB's FY25 half-year result, the bank revealed cash earnings of $1.63 billion in business and private banking, $576 million in personal banking, $909 million in corporate and institutional banking, and $781 million in New Zealand banking. 

Overall profitability is expected to rise in the coming years too. UBS predicts that NAB's net profit after tax (NPAT) will rise slightly to $7.08 billion in FY26 and reach $7.85 billion by FY29.

CBA's quarterly net interest income in the three months to 31 March 2025 was flat, with growth of lending volume offset by ongoing competitive pressure in deposits.

The bank also reported a loan impairment expense of $223 million, with collective and individual provisions slightly higher. CBA reported that portfolio credit quality had "remained sound".

While some analysts expect CBA's shares could have more room for growth, others predict that CBA shares are more likely to tumble. The significant share price premium versus competitors suggests it is already priced correctly, with no reason for rapid growth.

Westpac has been affected by broad weakness in the banking sector, which is pulling down its share price. The bank may benefit from increased demand for credit as interest rates continue to fall, but its net interest margin (NIM) may come under pressure as a result.

Westpac was the first of the big four banks to report interim earnings earlier this month, but it posted a 1% dip in profit to $3.3 billion.

ANZ currently offers the highest dividend yield of the big four banks, but its share price has been flat over the year, and down over the month.

ANZ reported its half-year results on 8 May, revealing strong profit and revenue growth, largely due to its acquisition of the Suncorp Bank business.