The National Australia Bank Ltd (ASX: NAB) share price handily outperformed the benchmark in August.
On 31 July, shares in the S&P/ASX 200 Index (ASX: XJO) bank stock closed trading for $28.42 apiece. On 31 August, shares closed the day at $28.96.
That put the NAB share price up 1.9% for the month.
Now, that's a solid performance over any given month.
But it's remarkably good, considering the ASX 200 fell 1.4% in August.
And with the other big four banks finishing the month in the red, the S&P/ASX 200 Financials Index (ASX: XFJ) declined even further, dropping 1.7% in August.
What helped the NAB share price outperform?
The biggest factor that looks to have buoyed the NAB share price over the month just past was the release of the company's third-quarter results on 15 August and a separate announcement of a major planned share buyback.
Among the highlights of the quarterly update, the bank reported a statutory net profit of $1.75 billion. And cash earnings were up 5.8% year on year to $1.9 billion.
On the negative side of the ledger, NAB's net interest margin (NIM) dropped 0.05% to 1.72%.
However, investors sent the NAB share price up 1.3% on the day, likely enticed by management's announced plans to buy back some $1.5 billion of shares on-market.
That plan was driven by the strength of the ASX 200 bank's CET1 ratio, which compares a bank's capital against its assets.
NAB reported a CET1 ratio of 11.9% for the quarter, significantly above its target range of 11.0% to 11.5%.
In general, when a listed company buys back a sizeable amount of its shares on-market, it tends to support the share price in the months ahead.
Commenting on the buyback that offered some tailwinds for the NAB share price, CEO Ross McEwan said, "This decision is consistent with our focus on maintaining a strong balance sheet through the cycle, while progressively reducing our share count over time."