What happened

Maybe you haven't heard, but...Elon Musk is buying Twitter (TWTR).

Earlier this week, the Tesla (TSLA 3.46%) CEO reached an agreement with Twitter's board to finalize the long-awaited sale for a $44 billion asking price. Of course, this means that Elon Musk must now come up with $44 billion.

Huge pile of cash in bundles of $100 bills.

Image source: Getty Images.

As it turns out, a lot of that cash is coming from sales of Tesla stock. As The Wall Street Journal just reported, between Tuesday and Thursday this week, Musk sold more than 9.6 million shares in order to raise $8.5 billion in cash toward the $21 billion in cash he's expected to contribute. Banks are expected to personally loan the megabillionaire $12.5 billion more (backed by $62.5 billion in Tesla shares put up as collateral for the loans), putting Musk over the top for the amount of cash he will need. Then even more banks will invest $25 billion more in the deal to take Twitter private.

There's a lot of money at play, but here's the good news for Tesla investors: As Musk tweeted out last night, the math is working as planned, and as a result, he won't need to sell any more Tesla stock to come up with his share of the Twitter purchase price. This tweet seems to be the reason Tesla stock is up 4.8% as of 10:30 a.m. Friday morning.

So what

And not a moment too soon! Now that we know for certain that Musk has been selling off his Tesla holdings to raise the cash for the Twitter deal, it makes a whole lot more sense why Tesla stock fell 12% between the end of last week and the close of trading last night.

Nearly 10 million Tesla shares suddenly flooding onto the market couldn't help but push the share price down. But now that that selling pressure has subsided, it's possible for Tesla stock to at least edge back up again. And here's even more good news:

Even after all the selling, Elon Musk remains Tesla's largest shareholder, with a 16% stake in the company -- 163 million shares, or roughly 17 times more shares than he sold.

Now what

If any investors were worried that Musk might lose interest in Tesla after acquiring Twitter -- that he might start to see himself more as a social media mogul than the driving force behind the movement to popularize electric cars -- well, this fact should set their minds at ease. What's more, as the Journal points out, "Mr. Musk has tens of millions of vested Tesla stock options [and] is in line to receive billions of dollars worth of additional stock options."

Much as Musk might love free speech, money still matters to him -- and with so much of his wealth tied to Tesla (which, according to S&P Global Market Intelligence data, earned $5.5 billion last year, by the way, while Twitter lost $221 million), I think it's safe to say that Musk's focus is going to remain quite tightly tied to Tesla.