By Noel Randewich
(Reuters) - Moderna (NASDAQ:MRNA)'s stock dropped 2% in a volatile session on Tuesday, with the COVID-19 vaccine maker the most heavily traded company on Wall Street ahead of its debut in the S&P 500 on Wednesday.
Over $34 billion worth of the company's shares were exchanged, 17 times more than Moderna's $2 billion average over the past six months, according to Refinitiv data. About $10 billion worth of those trades happened in the final seconds of the session.
Apple (NASDAQ:AAPL) was second-busiest stock, with about $14 billion worth of its shares traded.
After the bell, Moderna dropped an additional 1%, also in heavy volume.
Moderna joins the S&P 500 as of the start of trading on Wednesday. That means index funds managing over $5 trillion will have to have bought about 17% of the company's stock, according to Howard Silverblatt, a senior index analyst at S&P Dow Jones Indices.
Moderna's inclusion in the index also means that actively managed funds that measure their performance against the S&P 500 are more likely to consider buying its shares.
During Tuesday's session, Moderna surged as much as 9% and fell as much as 7%. The stock has gained about 18% since July 15, when S&P Dow Jones Indices announced its addition to the S&P 500.
The latest volatility in Moderna's stock comes as concerns increase over the highly contagious Delta variant of COVID-19, now responsible for the majority of new infections. Fears about a resurgence in the virus slammed Wall Street on Monday.
Fueled by the success of its COVID-19 vaccine, Moderna's stock has rallied almost 200% so far in 2021.