Sometimes, a significant jump in the 'Month change in Shares %' for a mutual fund's holdings in a specific stock can result from corporate actions, such as stock splits or bonus issues. 

When a company declares a stock split or bonus, shareholders, including mutual funds, receive additional shares. This increases the number of shares held, while the actual ownership stake in terms of market value remains the same.

Example:

Let's take Bharat Petroleum Corporation Ltd., which announced a bonus issue in the ratio of 1:1 with an ex-date of June 21, 2024. 

Due to this bonus issue, ICICI Prudential Bluechip Fund Growth saw its holdings in Bharat Petroleum double from 13,479,599 shares in May 2024 to 26,959,198 shares in June 2024. 

This increase was due to the 1:1 bonus declaration; while the number of shares has doubled, it does not necessarily indicate an additional investment by the fund in the stock.