Elon Musk just lost $3.3B on a double whammy

It's been an ugly stock market for most investors. But famed inventor and investor Elon Musk is having an exceptionally bad year - not just on one investment - but two.

Musk's holdings in solar panel installer SolarCity and electric car maker Tesla are down a staggering $3.3 billion - just this year.

Both Musk's companies have been falling out of favor with investors this year as the market punishes companies that are thin on profit but high on valuation. Falling oil prices have also taken out the urgency and enthusiasm over alternative energy plays.

Musk is now down $666 million in his shares of SolarCity on the year. The stock plunged 25% Wednesday to $19.56 after the company that installs and leases solar panels told investors late Tuesday it will likely lose up to $2.65 a share in the current quarter. That's deeper than the $2.49 a share loss investors were expecting.

Next, all eyes are on Musk's big investment: Tesla. Musk's massive $4.3 billion stake in the electric car maker makes his $419 million position in SolarCity look minor. Shares of Tesla are down 37% this year - serving up a nearly $12 billion loss to investors - of which Musk has eaten $2.6 billion of. Tesla is expected to report quarterly earnings after the market closes Wednesday. Investors predict the company to turn a profit of an adjusted 12 cents a share, reversing four-straight quarterly losses.

It's too soon to feel bad for Musk. His stakes in SolarCity and Tesla are still valued at $4.8 billion. That doesn't even include Musk's stake in space flight pioneer SpaceX, which is privately held.