PTC THERAPEUTICS, INC. (PTCT)

As of 14 August 2026, short interest in PTCT is 10,221,046 shares, up 387,066 shares over the last month. Over the last 48 readings it ranged from 3,696,224 shares (14 February 2025) to 17,315,032 shares (30 June 2026). At the reported average volume of 944K shares a day that is 10.8 days to cover, a crowded short.

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As of 11 September 2026, the short share of PTCT volume is 52.2%, down 17.8 points over the last five sessions. Over the last 52 readings it ranged from 38.3% (19 August 2026) to 85.4% (14 July 2026). The latest reading is 6.9 points below the 30-session average of 59.1%, on 358K shares reported.

As of 12 August 2026, the fails-to-deliver balance in PTCT is 2,757 shares, down 44,091 shares over the last settlement date. Over the last 52 readings it ranged from 3 shares (14 November 2025) to 375,002 shares (28 July 2026). The latest reading sits at the bottom of that range.

Insiders at PTCT reported 43 open-market sells worth $15.5M in the last 90 days and no open-market buys. Sells alone are a weak signal; insiders sell for tax, diversification and estate reasons all the time. Latest filing: SCHMERTZLER MICHAEL on 2026-09-10.

Form 4 filings are due within two business days of the trade. Insiders sell for many reasons that say nothing about the company; open-market buys are the rarer, stronger signal.

3 Form 144 notices on file for PTCT worth $1.2M at the prices reported; 3 in the last 90 days worth $1.2M. Latest: Boulding Mark Elliott filed on 2026-08-17 to sell 2,813 shares ($202K) from 2026-08-17.

7 of the 30 tracked managers held PTCT at their latest 13F, $283.0M in total at quarter-end prices. D. E. Shaw & Co. is the largest at $126.3M (0.1% of its portfolio) as of 2026-06-30. Over the prior quarter 2 added shares and 5 cut.

Only the 30 tracked managers on the funds hub; a 13F reports long positions in US listed stock at quarter end, 45 days late, and says nothing about shorts or positions sold since.

In Q2 2026 (quarter ended 2026-06-30) PTC THERAPEUTICS, INC. reported revenue of $360.5M, up 101.5% from the same quarter a year earlier, and net income of $83.5M (0.92 diluted EPS). In FY 2025 it generated $711.2M of operating cash flow. As of 2026-06-30, cash was $1.05B against $535.5M of debt.

Quarterly, last 8 quarters

Fiscal years, with buybacks and dividends

Quarters are the three-month figures the company reports; a fourth quarter marked derived is the fiscal year less the three reported quarters, since companies report it only inside the 10-K. Fiscal years are the annual figures. Buybacks are cash paid to repurchase common stock in the year (XBRL PaymentsForRepurchaseOfCommonStock), not authorizations. Balance sheet lines are as of 2026-06-30; shares outstanding as of 2026-07-29 from the cover page.