Do market makers keep stock prices artificially low in the week just before the options expirations date? Simply because someone told me about this and I wondered if it might have a major or minor effect on stock prices?

If they do have a lowering effect on the stock price, it would seem the
logical thing to do would be to buy options that expire after the upcoming
expiration date during the period just before the upcoming expiration date.

Hi madden1962 and welcome to FM.

As for your question - if you're talking about stock options then why should they share any bias toward call options? If a stock has a large open interest on puts, then wouldn't the market makers do the opposite of what you suggest?

I guess if you really wanted to test this you could do so easily enough yourself - just look at what the underlying tends to do right after option expiration, and see if it's statistically different from what the underlying does at any other time.

Hope that helps.

If its fishy and possible, the brokerages are doing it.