SoftBank tightened the reins to curb the excesses of startup founders after the spectacular, multi-billion dollar failure of WeWork forced the tech investor to take huge losses and take a hard look at its mistakes.

The Japanese bank outlined stricter guidelines and standards regarding dual-class share structures on Wednesday after reporting its first quarterly loss in 14 years. SoftBank announced a writedown of almost $4.6 billion in the value of its investment in WeWork, the company reported. There were also writedowns in the value of Uber and other investments.

“In the case of WeWork, I made a mistake,” SoftBank CEO Masayoshi Son said at a press conference in Tokyo. “I won’t make any excuses. It was a very harsh lesson.”

Silicon Valley startup founders typically have been allowed a great deal of autonomy by investors, but SoftBank’s travails with WeWork and Uber signal retrenchment. Those companies are just the best-known that have caused problems for the bank’s almost $100 billion Vision Fund, which lost $8.9 billion.

SoftBank’s new governance standards will apply to future investments. The bank’s Saudi Arabia-backed Vision Fund has yet to decide whether it will apply some or all of the rules. 

“In the case of WeWork, I made a mistake. I won’t make any excuses. It was a very harsh lesson.”

WeWork, an office-sharing company, went from being one of the most eagerly awaited IPOs with an estimated value of as much as $47 billion to near failure in a matter of weeks. The company’s CEO and co-founder Adam Neumann had to step down in September after his mistakes and potential conflicts of interest helped derail the IPO scheduled for that month. The real estate concern turned out to be hemorrhaging cash and in dire need of a savior.

SoftBank spent $9.5 billion to rescue WeWork in October. Part of this cash infusion went to paying for an unrivaled $1.7 billion exit package for Neumann. While WeWork’s co-founder can retire comfortably, the company’s 14,000 employees face the prospect of layoffs, and now hold almost-worthless stock options. Prior to the rescue the Wall Street Journal said that WeWork was delaying layoffs until it had enough cash for severance.

Uber is another SoftBank venture that’s been bleeding cash. Uber has lost more than a quarter in value since going public and cost the Japanese firm $600 million so far, CNBC said. Uber reported a staggering $1.2 billion third-quarter loss this week.

  • SoftBank reported profit for the six months ended in September of almost $3.9 billion, about half the level from a year earlier. The figures imply that SoftBank lost more than $6.4 billion in the most recent three-month period, the paper said.
  • The Vision Fund’s biggest investment, $11.8 billion in Chinese ride-hailing company Didi Chuxing Technology Co. is also in trouble, according to the Wall Street Journal
  • SoftBank’s Son has seen his net worth tumble about $6 billion from its peak in July because of his bad bets on technology startups, Bloomberg News reported.