(Reuters) -Septerna's shares rose about 31% in their market debut on Friday, giving the Goldman Sachs ( GS )-backed biotech firm a valuation of $970 million.

The company's shares opened at $23.5 in their Nasdaq debut, compared with the IPO price of $18. Septerna upsized its offering twice on Thursday to sell 16 million shares, to raise $288 million.

Biotech firms' public listings have received a warm reception from investors this year, with September being one of the busiest months for healthcare IPOs, as per Dealogic data.

Biotechnology firms MBX Biosciences and TPG-backed Bicara Therapeutics went public last month, with shares trading 33% and 25.6% above their IPO prices, respectively.

The Federal Reserve's move to begin monetary policy easing last month, along with an ebullient equity market are key aspects set to guide investor optimism for fresh listings entering the market this fall.

California-based Septerna is developing therapies targeting G-protein-coupled receptors (GPCR), a class of proteins that serve as a main conduit for chemicals to get past a cell's membrane and be taken up by a cell.

GPCR can influence broad physiological processes such as metabolism, secretion, cell growth, and immune responses.

The company will use proceeds to advance its research and develop its products, including SEP-786, its lead candidate for treating hypoparathyroidism, a condition that disrupts calcium levels in the blood and bones.

J.P. Morgan, TD Cowen, Cantor and Wells Fargo Securities are acting as the joint bookrunners for the IPO.

Goldman owns a 5.4% stake in the company, while healthcare-focused venture capital firm Third Rock Ventures holds 33.5%.