All stocks have some “noise” in them. For MA, it’s probably 1%-2%. Any move that’s less than 2% for MA I ignore. It’s just people moving in and out for reasons likely unrelated to the business. For more lightly traded stocks, the number is higher, maybe 5%.
Reading the MF SA Mastercard board I came on this wonderful quote by Craigrow in answer to a question about why the stock dropped 1.5%. I thought his response was wonderful and very useful for us all to keep in mind.