Apple, the world's most valuable company, added more worth in one day than the market cap of nearly 400 individual companies in the S&P 500.
The smartphone maker's shares surged 6 percent to a new all-time high at Wednesday's open, a day after it reported better-than-expected earnings. The gain represented $48.1 billion of additional value for Apple shareholders to an approximately $830 billion total market value.
The single-day increase is more than the market value of Ford Motor and 392 companies in the S&P 500, according to FactSet.
Apple's stock closed up 5 percent Wednesday.
The technology company has been one of the best-performing large-cap stocks in the market. Its shares rallied 29.6 percent year to date through Tuesday versus the S&P 500's 10.6 percent return.