Skip to navigationSkip to main contentSkip to right columnADVERTISEMENTSean Williams, The Motley FoolSat, June 20, 2026 at 3:26 PM GMT+2 6 min readA little more than a week ago, Space Exploration Technologies (SpaceX) (NASDAQ: SPCX) cemented its place in Wall Street history by raising $75 billion with its initial public offering (IPO) and debuting as one of the largest companies in the world.After only three trading sessions (through June 16), Musk's artificial intelligence (AI) and space economy titan commanded a $2.66 trillion valuation, placing it ahead of some of Wall Street's most influential businesses, such as Amazon, Broadcom, and Musk's other trillion-dollar company, Tesla.Missed Nvidia in 2009? This Rare Signal Is Flashing Again. In 2009, a "Double Down" signal flashed for a little-known chipmaker called Nvidia. For the first time in years, that same "Total Conviction" signal is flashing for a company 1/100th the size of Nvidia. Continue »Several factors have positioned SpaceX stock for early success. But these early gains can quickly turn into a nightmare for retail investors once SpaceX's unique lockup period takes effect.Image source: Getty Images.Although investor euphoria for the SpaceX IPO has been off the charts, it's the structural changes to major index inclusion and SpaceX's historically low float that are primarily responsible for its stock rocketing out of the gate since June 12.Long before SpaceX went public, several oversight committees amended the rules governing index inclusion. It began with Nasdaq (NASDAQ: NDAQ) Global Indexes refreshing the rules for inclusion in the growth-stock-dominated Nasdaq-100. Effective May 1, low float requirements for the Nasdaq-100 were waived, and companies that would rank among the 40 largest in the Nasdaq-100 are eligible for fast-entry inclusion after just 15 trading sessions. This is down from a previous wait period of around three months.Less than four weeks later, the U.S. Russell Equity Indexes amended its rules ahead of the SpaceX IPO. Instead of reviewing newly public large-cap companies for inclusion once per quarter, giants like SpaceX can be added to the appropriate U.S. Russell Indexes after only five trading days.These structural index changes grant SpaceX fast entry into the Nasdaq-100, Russell 1000, and Russell 3000 indexes. More importantly, it forces passive funds that attempt to track these indexes to purchase SpaceX stock shortly after its IPO. This forced buying can translate to tens of billions of dollars in demand.Additionally, SpaceX sold approximately 555.6 million shares for its IPO, representing a little over 4% of its outstanding shares. Most companies that are going public sell 10% to 25% of their outstanding shares.Terms and Privacy PolicyEU DSA contactPrivacy & Cookie SettingsMore Info