The S&P/ASX 200 Index (ASX: XJO) has not enjoyed a great month over the past four weeks. As it stands on today's market moves, the ASX 200 has slipped by around 0.51% compared to this time in August.
But one major ASX 200 constituent has fared worse than the ASX 200 over the past month. That would be the ASX 200's largest bank (and presently largest company), Commonwealth Bank of Australia (ASX: CBA).
The Commonwealth Bank share price has underperformed the ASX 200 over the past month. While the ASX 200 has gone backwards by around 0.51%, CBA shares have gone from just under $105 a share a month ago to today's share price (at the time of writing) of $101.83 a share. That's a slide of around 3%.
So why this struggle for the CBA share price?
Why has the CBA share price underperformed the ASX 200 over the past month?
Well, it's important to note that ASX bank shares have been a hard-hit sector during the widespread lockdowns of the past few months. As my Fool colleague Kerry discussed last week, the ASX banks may be struggling with slowing housing and credit growth, as well as the potential of customers and businesses struggling to service loans in these difficult times.
After the initial excitement following CBA's earnings results last month, this could well be a factor in the recent poor run for the CBA share price.
But that brings us to a second possible catalyst for CBA's poor performance: its recent dividend and share buyback program.
During its FY21 earnings report, CBA announced a well-received final, fully franked dividend of $2 per share, alongside a $6 billion share buyback program. This payout went ex-dividend on 17 August which resulted in a 3% share price drop that day
New owners of CBA at and after this date are not eligible to receive this dividend, so it makes sense that its value leaves Commonwealth Bank's market capitalisation. CBA closed access to its share buyback offer the day before, on 16 August.
Both of these actions evidently resulted in investors adjusting the CBA share price accordingly. As such, these events are likely a major reason why CBA shares have gone backwards over the past month.
At the current CBA share price, this ASX bank has a market capitalisation of $180 billion, a price-to-earnings (P/E) ratio of 21.67 and a dividend yield of 3.43%.
