A sharp pullback in Tesla and SpaceX valuations has significantly reduced Elon Musk's paper fortune, according to the report. The decline is estimated to have erased roughly $650 billion to $700 billion in value from recent gains tied to his holdings in the two companies.

Tesla, the electric vehicle and energy business, and SpaceX are closely linked to Musk's overall net worth because much of his wealth is tied to his ownership stakes. When valuations in those companies rise, his estimated fortune can surge quickly. When they fall, the reversal can be just as dramatic.

The reported hit is to paper wealth rather than cash already taken out. In other words, it reflects a drop in the market or estimated value of Musk's assets, not necessarily a realized loss from selling shares or stakes.

The move highlights how concentrated billionaire wealth can swing with changes in investor sentiment and company valuations. It also shows how much of Musk's recent increase in wealth depended on strong performance at Tesla and SpaceX, and how quickly those gains can shrink during a selloff.