X0306 4 2018-07-12 0 0000730272 REPLIGEN CORP RPGN 0001270264 EDDLEMAN ROY T C/O TROYGOULD PC 1801 CENTURY PARK E., 16TH FLOOR LOS ANGELES CA 90067 0 0 1 0 Call option (obligation to sell) 54.9298 2018-07-12 4 S 0 1 1000000 D 2020-01-13 2020-01-13 Common Stock 250000 1 I As trustee Put option (right to sell) 43.4992 2018-07-12 4 P 0 1 1000000 A 2020-01-13 2020-01-13 Common Stock 250000 1 I As trustee The reporting person entered into a so-called zero-cost collar arrangement pursuant to which he wrote a covered call option and purchased a put option. Only one of the options can be "in the money" on the expiration date, at which time the in-the-money option will be exercised (and settled in cash) and the other option will expire. If neither option is in the money on the expiration date, both will expire. The securities shown are held of record by the Roy T. Eddleman Living Trust UAD 8-7-2000, of which the reporting person is the sole trustee, and as such, has investment and voting control over such securities. Istvan Benko, as Attorney-in-Fact for Roy T. Eddleman 2018-07-16