Moderna has launched the largest initial public offering for a biotech, an IPO that raised at least $604.3 million in gross proceeds for the developer of messenger RNA (mRNA) treatments.

That figure could go higher, as its shares debut for trading today on the NASDAQ Global Select market under the ticker symbol “MRNA.”

Moderna last night offered 26,275,993 shares of common stock at $23 a share. While the price fell at the midpoint of a previously-announced range of between $22 and $24 a share, the company sold 4,536,862 more shares than previously projected.

Just last week in its S-1/A amended registration statement, Moderna predicted it would sell 21,739,131 shares, even as it registered an even 25 million shares—a figure that included 3,260,869 shares that the IPO’s underwriters had an option to purchase.

Moderna has since upsized its IPO, yesterday registering an additional 5,217,391 additional shares. Moderna has also upsized the number of its shares that underwriters have the option to buy to an additional 3,941,398 shares of common stock, up from the initial 3,260,869 additional shares at the public offering price, less underwriting discounts and commissions on the same terms.

Should Moderna maintain or increase its share price today, the upsizing of the IPO will have increased Moderna’s net proceeds. The company previously estimated that at $23 a share, its IPO would raise net proceeds of approximately $465.5 million—rising to $536.4 million if underwriters exercised in full their option to purchase additional shares.

The upsized IPO values Moderna at about $7.5 billion.

“I don’t understand how you get to that valuation,” analyst David Nierengarten of Wedbush told Bloomberg News. “Not only are they early stage, but they’re looking at pretty long and expensive development timelines.”

21-Program Pipeline

Headquartered in Cambridge, MA, Moderna and its collaborators have advanced a development pipeline of 21 programs since the company’s inception in 2010—of which 10 have entered clinical studies and another three have open INDs. The company’s therapeutic and vaccine development programs span infectious diseases, oncology, cardiovascular diseases, and rare genetic diseases.

Last week in its amended IPO registration statement, Moderna broke down how it intended to use its net proceeds from the offering.

More than half the net proceeds—approximately $315.0 million to $345.0 million—would fund drug discovery and clinical development, further expansion of Moderna’s manufacturing platform and capabilities, and infrastructure to support its pipeline, the company stated.

Approximately $75 million to $85 million of the proceeds would fund further development of its mRNA technology platform and the creation of new modalities. The remainder of the proceeds—between $170 million and $210 million—would fund working capital and other unspecified general corporate purposes.

“We may also use a portion of the net proceeds to in-license, acquire, or invest in complementary businesses or technologies to continue to build our pipeline, research, and development capabilities, and our intellectual property position, although we currently have no agreements, commitments, or understandings with respect to any such transaction,” Moderna stated in its amended IPO filing—using wording identical to its initial filing.

Morgan Stanley, Goldman Sachs, and J.P. Morgan are acting as joint lead book-running managers for the offering. BofA Merrill Lynch, Barclays Capital, and Piper Jaffray & Co. are acting as book-running managers, while Oddo BHF SCA, Oppenheimer & Co., Needham & Company, and Chardan are acting as co-managers.