X0306 4 2015-03-02 0 0001401708 NanoString Technologies Inc NSTG 0001225501 JOHNSON JAMES A 530 FAIRVIEW AVENUE N. SUITE 2000 SEATTLE WA 98109 0 1 0 0 Chief Financial Officer Common Stock 2015-03-02 4 A 0 789 9.52 A 2948 D The reporting person is voluntarily reporting the acquisition of shares of the issuer's common stock pursuant to the NanoString Technologies, Inc. Employee Stock Purchase Plan ("ESPP"), for the ESPP Purchase Period (as defined in the ESPP) of September 2, 2014 through March 2, 2015. This transaction is also exempt under Rule 16b-3(c). The Purchase Period ended on March 2, 2015 and is the first of two Purchase Periods comprising the Offering Period (as defined in the ESPP) that began on September 2, 2014. In accordance with the ESPP, these shares were purchased based on 85% of the closing price of the issuer's common stock on March 2, 2015. /s/ Shannon Atchison, Attorney-in-fact 2015-03-04