Brown raised more than $4 million in 2014, and spent $232,000 in that time, his report shows.
Brown's top contributors in the most recent campaign finance reporting period, which spans from mid-March to Mid-May, included Yahoo CEO
Each gave $27,200, the maximum allowed by law.
Microsoft also contributed $23,800 to the governor's campaign.
Among the governor's primary challengers, Republican Neel Kashkari already has invested $2 million of his own cash in a bid for the governor's office. Earlier this week, Kashkari said he wouldn't rule out tapping into his personal bank account in the future.
The most recent campaign finance reports were not available for Kashkari, a former U.S. Treasury official, or his main GOP rival in the race for the gubernatorial nomination, Assemblyman
Thursday is the deadline for all candidates to file their latest campaign finance reports to the California Secretary of State.
California's primary election is Tuesday, June 3.