Shares of Livent Corp. were plunging 22% in afternoon trade, on track for their worst performance by far since going pubic in October, after the lithium producer reported first-quarter sales that missed expectations and lowered its full-year outlook. The results were reported after Tuesday's close. The previous biggest one-day drop was 9.6% on Dec. 20. The stock was now trading 51% below its initial public offering price of $17. Trading volume ballooned to 10.9 million shares, or nearly 5 times the 5-day average. Livent shares have tumbled 39.6% year to date, while the Renaisssance IPO ETF has run up 32.9% and the S&P 500 has gained 15.3%.