The purchases were made Tuesday and today, according to the filing. With the additional purchases, Musk now holds 33,737,921 shares in a trust.
At Tesla's closing price of $344.78 Wednesday, that makes Musk's stake worth approximately $11.6 billion.
Tesla announced extensive job cuts Tuesday in a bid to save money and speed its way to profitability. Tesla has been burning through cash as it struggles to ramp up production of its mass market Model 3 electric vehicles.