Masayoshi Son has sharply accelerated the pace of his startup investments this year, quintupling the number of companies in his Vision Fund 2 portfolio in less than nine months.

The founder of SoftBank Group Corp. has cut 115 deals this year, according to Bloomberg calculations based on data released by the company. That is more than the combined number of deals the first Vision Fund made since its start in 2017, showing Son remains confident in his investing capability despite blunders with office-sharing service WeWork and financier Greensill.

The faster pace of deal-making is sure to raise questions about whether Son is risking similar missteps, especially as a string of high-profile departures depletes top talent at the Vision Fund. Seven managing partners have left since March of last year, and last week Deep Nishar, the sole senior managing partner and leading authority on AI, said he would depart by the end of the year.