Tesla raised $1.8 billion, $300 million more than expected, in its first high-yield junk bond offering Friday.

The yield of 5.30 percent was slightly higher than the original guidance of 5.25 percent.

Earlier in the week, Elon Musk's luxury electric car maker was expected to raise at least $1.5 billion to accelerate production of its new Model 3, but strong demand allowed the carmaker to raise more, albeit at a slightly higher yield than expected.

Goldman Sachs was the lead underwriter of the eight-year bonds. S&P rated the bonds negative B and Moody's B3.

"It was well-received," said Efraim Levy of CFRA. "In a large extent it does show that people are interested in the bonds of the company because they believe in the long-term growth ... story."

Levy noted that investors are expecting profitability from Tesla's more affordable Model 3. "By 2025 there's no more room for excuses," he said.

Tesla has burned through billions of dollars — $1.2 billion in cash in the second quarter alone — in its effort to develop electric cars.

"The issuer will use the net proceeds from this offering to further strengthen its balance sheet during a period of rapid scaling with the launch of Model 3, and for general corporate purposes," Tesla said in the debt offering term sheet.

Morgan Stanley; Barclays Capital; Merrill Lynch, Pierce, Fenner & Smith; Citigroup Global Markets; Deutsche Bank Securities; and RBC Capital Markets were the other underwriters.

The debt pricing came amid a more than 1 percent drop this week in the iShares iBoxx $ High Yield Corporate Bond ETF (HYG), which held gains of less than 1 percent for the year Friday, as geopolitical risks soured the appetite for risky assets.

That made it all the more surprising that Tesla would be able to raise more money than expected and at such a reasonable yield for a company with a risky balance sheet.

It "speaks to the sheer insanity found in the high-yield market to have a deal like this upsized with terms so unappealing to investors," said Larry McDonald, author of The Bear Traps Report newsletter. "The deck is stacked for Tesla in bond deal terms, congrats to Elon Musk."