A lot of Americans are about to own a sliver of SpaceX.<\/p>\n
The company completed its initial public offering<\/a> Friday in the world\u2019s largest stock market debut \u2014 and in a few days many personal and retirement investment accounts will have a stake in it<\/a>, largely through index funds that track the broader market.<\/p>\n Below, you can estimate how much of SpaceX and other companies you\u2019d own if your investments were in various index funds:<\/p>\n In the context of other index fund holdings, SpaceX will probably take up a smaller portion than one might expect, because most of its stock is not publicly tradable yet. Other major tech companies, like Nvidia and Apple, will continue to make up a much larger share of index funds compared with SpaceX, at least for now.<\/p>\n And most typical retirement accounts already have a bigger investment in another Elon Musk venture. According to our estimates, investors in total U.S. stock market index funds will own more than 10 times as much Tesla stock as they do SpaceX.<\/p>\n Our calculator can\u2019t predict the future, so it makes a few major assumptions. It assumes that when index funds will buy into the company, its shares will be at $150, the opening price Friday.<\/p>\n This probably won\u2019t be the case, and in fact the price may even push up in anticipation of when the index funds will buy their shares, according to John Shim, assistant professor of finance at Notre Dame.<\/p>\n \u201cBuying immediately after the I.P.O. in the days that follow is usually a very bad idea,\u201d he said.<\/p>\n Some indexes have changed their rules to more quickly include new mega I.P.O.s in their baskets of stocks, on the idea that these companies are now often more mature<\/a>, more integrated into the economy and less volatile at the time they go public. The CRSP U.S. Total Market Index, which is used by large investment management companies like Vanguard as a benchmark for index funds, is planning to integrate the company five days after its market debut. That\u2019s one reason many average investors will have a stake in SpaceX very quickly.<\/p>\n The Nasdaq-100 index, while not common in retirement accounts, is set to introduce SpaceX 15 trading days after the I.P.O. It is even multiplying the value of SpaceX by three to account for a low initial \u201cfloat,\u201d or number of shares available for investors \u2014 so people who invest in the Nasdaq-100 (by holding the QQQ E.T.F., for example) will have a bigger stake in the company.<\/p>\n