Super Micro Stock and Deckers Surge. They’re Joining the S&P 500 Index.

The changes will take place before the opening of trading on March 18 and coincide with the quarterly rebalance of the indexes. S&P Dow Jones Indices said the market values of the four companies are more representative of their new indexes.

Super Micro, a maker of servers that help with artificial intelligence applications, has been one of the hottest stocks this year with the company’s shares more than tripling. The stock was up 4.5% Friday to $905.48 in regular trading and added another 16% to $1,048 in premarket trading on Monday.

Super Micro has been the biggest driver of the gain in the S&P MidCap 400 index this year as well as the
Russell 2000
index, where it is the largest component.

Super Micro now is valued at more than $50 billion, which made it by far the largest company in the S&P MidCap 400 index and it should be bigger than most companies in the
S&P 500
index when it joins, assuming no major drop in the stock in the next two weeks.

Deckers, the maker of Ugg shoes and the popular Hoka sneakers, is valued at about $22 billion. Its shares are up about 35% this year. Its stock gained 0.9% to $903.29 in regular trading Friday and was up another 4.5% on Monday.  

Both Whirlpool and Zions are valued at about $6 billion. Whirlpool was off 1% to $105.72 in Monday trading while Zions was down 1.8% at $38.07.

Write to Andrew Bary at [email protected]