Mesoblast Ltd's stock fell sharply by 5.14% during Tuesday's intraday trading session. The biotech company's shares experienced significant selling pressure despite recent positive insider activity.

The move follows news that the company's CEO exercised 1.9 million options at A$1.45 each for a total of A$2.73 million and increased share ownership to 80.8 million shares. Typically, such insider buying is viewed as a vote of confidence in the company's future prospects.

However, investor sentiment appears to have been weighed down by broader concerns highlighted in recent analysis. Mesoblast, while having the first FDA-approved mesenchymal stromal cell product in the U.S. and over 1,100 patents, remains unprofitable and carries funding risk. The company trades on a rich price-to-sales multiple, raising questions about whether future growth can justify both the current balance sheet and valuation.