Mutual funds generally buy stocks in lots, i.e. they bulk buy stocks. Given the quantities they transact in, they do influence the price of a particular stock. However, as a result of this, the effect on the overall market is negligible. Even while buying or selling shares of a particular company/companies, they buy it in lots.

This helps in staggering the fluctuations in prices as a result of their transactions. Seemingly, there are protocols set in place for mutual funds by the Securities and Exchange Board of India (SEBI) so as to avoid any wrongdoing as a result of their effect on a particular stock. Of course, when we consider a bull run or a bear phase, the impact of mutual fund buying/selling is amplified and widespread. But these are exceptional cases and have no impact on everyday trading.