A dividend paying asset pays a dividend on a specific date. When brokerages auto-reinvest these proceeds (DRIP), won't that influence the price (assuming that it's a market order)? In other words, wouldn't there consistently be a spike in price the day after a dividend is paid out?
For reinvestment of dividends, brokers combine the expected cash distributions to be received from dividends and they then purchase shares at the open on the payable date. Some studies indicate that this creates buying pressure that results in an increased share price as the dividend payout date approaches. Some authors suggest that share price then drops after the payable date.
OTOH, traditional Dividend Reinvestment Plans (DRIP) with the company, the dividends purchase the shares directly from the company's treasury stock. When sold, such shares are sold back to the company. So these DRIPs have no effect on share price.