The 180-day lockup period for Castle Biosciences Inc. (CSTL) ends on January 21, 2020. When the lockup ends, company's pre-IPO shareholders and insiders may choose to sell more than 10.4 million shares of CSTL in the secondary market. The number of currently-restricted shares dwarfs the 4 million shares of CSTL offered in the IPO and significant sales of currently-restricted stock could flood the secondary market and negatively impact the stock price of CSTL when the lockup expires.
Trading in Castle Biosciences has been somewhat mixed during this six-month period, but CSTL