Gossamer Bio, Inc. announced that it has raised $100,000,000 in its seed round of funding co-led by Arch Venture Partners, L.P. and Omega Fund Management UK LLP on January 4, 2018. The company issued series A preferred stock in the transaction. As part of the transaction, Richard Lim and Otello Stampacchia of Omega Fund Management UK LLP and Kristina Burow and Robert Nelsen of Arch Venture Partners, L.P. The company will issue securities pursuant to exemption provided under Regulation D.