SoftBank's Vision Fund went from being in the red, with an annual operating loss of $18 billion at one point, to an $8 billion net profit in its most recent quarter — thanks in no small part to the past year's unexpected events.

Why it matters: While the Vision Fund's bet on a global shift to digital services is likely correct, it's hard to believe its financial performance would have rebounded so quickly had 2020 gone differently.

The pandemic...

• It's been a huge accelerant for trends central to Vision Fund's thesis and many of its portfolio companies — food delivery, online education, e-commerce, and so on.
• SoftBank's defensive moves in the spring, including stock buybacks and writing down more poorly performing companies, put it a position to benefit even more from the surprising boom on the stock market that followed.
• Even WeWork—which fell so hard, so fast when it tried to go public in 2019 — could be the one office co-working company left standing after the pandemic. Regus properties have been filing for bankruptcy (and its parent company just acquired a majority stake in embattled women-focused clubhouse The Wing), as has Knotel, another venture-backed rival that was once valued at $1.6 billion.

The stock market...

• It didn't get the memo that there's a global pandemic and massive economic hit — it just kept going up and to the right.
• 11 of SoftBank's portfolio companies have gone public since the pandemic began, helping to contribute to the Vision Fund's $13 billion in investment gains just in the last quarter.
• Even portfolio companies that were already public performed well, adding to the fund's recent success.

The other side:

• For one, luck isn't everything — the fund's performance is tied to CEO Masayoshi Son's fundamental investment thesis staying focused on digital technologies.
• A great market won't do very much for a portfolio of weak companies that won't be able to go public or continue to grow in value. In short: SoftBank did well in picking eventual winners.
• And now, three-and-a-half years into the Vision Fund, SoftBank is past the trough of the expected J-curve, which is par for the course in venture investing. As they say: things get worse before they get better.

The bottom line: "Luck is what happens when preparation meets opportunity," Roman philosopher Seneca once wrote.