Seaport Therapeutics, Inc. (SPTX)

Price$23.94Cached quoteAs of 2026-09-04 16:23 UTC

AI: Fair-priced

Price checkThe price gives substantial value to unproven medicines, balanced by a well-funded balance sheet.

With 53.53 million shares outstanding, the quote implies a market value near $1.25 billion, about 30% above the initial offering price. Against $427.3 million of cash and investments, buyers are assigning roughly $820 million to an unapproved pipeline. That is demanding because Seaport has no revenue and no demonstrated patient efficacy for its lead medicine. Yet funding through 2029 and two clinical programs make an extreme discount equally hard to defend. The evidence supports a fair-priced verdict, but with a very wide outcome range.

Big pictureSeaport has no sales, rising research costs, and enough cash to reach major trial results.

Seaport reported no revenue in 2024 or 2025. Its net loss widened from $46.9 million to $74.9 million, while operating expenses rose from $52.4 million to $87.3 million. During the first half of 2026, operating cash use increased to $46.3 million from $35.5 million, as research spending nearly doubled to $46.0 million. Operating cash use approximates free cash flow here—cash left after running and investing—because equipment spending was negligible. Simple annualization suggests several years of funding, though later-stage trials should raise costs.

Business strengthMultiple drug programs spread risk, but no candidate has proven patient benefit yet.

At June 30, cash and investments totaled $427.3 million, while all liabilities were only $19.1 million; management expects funding into 2029. The bull case is that GlyphAllo uses a familiar brain mechanism in an oral form, and its 33-person driving study found no next-morning impairment at tested doses. GlyphAgo adds a second path into anxiety treatment. The bear case is that these findings came mainly from healthy volunteers, not patients. Sales would also carry 3% to 5% royalties under transferred platform rights, reducing future economics.

What could change the storyStrong patient results could unlock value, while failure or heavy share issuance would hurt.

The clearest test is BUOY-1, with depression results expected in the first half of 2027. Convincing patient benefit would justify much of the roughly $820 million pipeline value; weak efficacy could erase it because there are no product sales. This business follows trial cycles, not ordinary economic cycles. Financing also matters: the May offering sold 14.45 million new shares, while 12.23 million employee options remained outstanding at June 30, equal to 23% of current shares before exercise proceeds. Cash is funding trials, with no dividends or buybacks.

AI: News

Driving Study Clears TestGlyphAllo avoided next-morning driving impairment, supporting safety but not proving depression relief.

On September 9, a randomized study of 33 healthy volunteers met its main test: repeated evening dosing at 375 milligrams did not worsen next-morning simulated driving versus placebo. A single 250-milligram dose also passed, and no serious adverse events occurred. The result supports a potentially useful safety difference, but BUOY-1 must still demonstrate benefit in depression patients. Shares closed 9.6% lower that session despite the positive announcement; timing alone does not show that the news caused the decline.

Funding Runway ConfirmedSecond-quarter results showed ample funding alongside sharply higher spending as trials advanced.

On August 3, Seaport reported $427.3 million of cash and investments and said this should fund operations into 2029. Second-quarter research spending increased to $24.6 million from $13.4 million as GlyphAllo and GlyphAgo advanced. The $62.6 million quarterly loss included unusually large non-cash employee-share costs tied mainly to the public offering, so it overstated cash consumption. The update also kept BUOY-1 depression results on track for the first half of 2027.

Upsized Public OfferingThe public offering greatly extended the cash runway but substantially increased the share count.

The offering priced on April 30 and closed in May, ultimately selling 14.45 million new shares and producing about $238.4 million of net proceeds after fees. That financing protects the clinical program from near-term funding pressure and should carry Seaport through several planned readouts. It also diluted earlier owners. Separately, preferred securities converted into 36.27 million common shares at the offering, largely explaining why reported common shares rose from 2.60 million at year-end to 53.53 million by June.

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Revenue

2024

2025

Net income

2024

2025

Free cash flow

2024

2025

Total cash / debt

CashTotal debt

2024

2025

Financial statements

	2025	2024
Revenue	$0	$0
Research & development	$1,000	$0
Operating expenses	$87.3M	$52.4M
Operating income	−$87.3M	−$52.4M
EBITDA	−$85.9M	−$52.2M
Net income	−$74.9M	−$46.9M
Basic EPSper basic share	-$1.94	-$1.21
Diluted EPSper diluted share	-$31.54	-$49.72

Review official source filings ↗

Owners

Reported shareholders

Reference date Jun 30, 2026

≈31.17%of listed shares

PureTech Health plc / PureTech LYT, Inc.16.69M shares · May 4, 2026

View holders

Top 20 reported holders of SPTX
Holder	% owned
PureTech Health plc / PureTech LYT, Inc.	≈31.17%16.69M shares
ARCH Venture Partners XII, L.P. / ARCH Venture Partners XII, LLC / NELSEN ROBERT / Burow Kristina / GILLIS STEVEN / ARCH Venture Fund XII, L.P. / CRANDELL KEITH	≈11.76%6.29M shares
ARCH Venture Management, LLC	11.76%6.29M shares
GENERAL ATLANTIC, L.P.	11.40%6.1M shares
General Atlantic GenPar (Lux) SCSp / General Atlantic (Lux) S.a r.l. / General Atlantic Partners (Lux), SCSp / GAP Coinvestments CDA, L.P.	≈11.40%6.1M shares
Sofinnova Investments, Inc.	6.66%3.56M shares
HEALY JAMES	≈5.10%2.73M shares
GOLDMAN SACHS GROUP INC	4.07%2.18M shares
TRV GP VI, LLC	3.85%2.06M shares
CANADA PENSION PLAN INVESTMENT BOARD	3.69%1.98M shares
JPMORGAN CHASE & CO	3.39%1.82M shares
Foresite Capital Management VI LLC	3.32%1.78M shares
PRICE T ROWE ASSOCIATES INC /MD/	2.44%1.31M shares
Zohar Daphne	≈2.23%1.19M shares
FMR LLC	2.21%1.19M shares
Bellevue Group AG	2.05%1.1M shares
Siren, L.L.C.	2.05%1.1M shares
JENNISON ASSOCIATES LLC	2.02%1.08M shares
PAUL STEVEN M	≈1.61%863.03K shares
RA CAPITAL MANAGEMENT, L.P.	1.31%700K shares

Percentages use 53.53M shares of this listed class outstanding on Jun 30, 2026. ≈ compares the latest reported holding with a share total from a different date; it is not a confirmed current stake.

Reported positions exceed 100% in total, so the circle shows the selected holder only.

Source: SEC Form 4 ↗Updated Sep 29, 2026 · Quarterly data

Insider buys & sells

Jul 1, 2024–Jun 30, 2026

Buys2$20.04M disclosed value

Sells (SEC code S)0$0.00 disclosed value

Transaction	Insider	Type	Shares	Price	Value	Owned after
Jun 22, 2026Form 4	HOMBACH ROBERT J.Director	BuyCommon Stock · indirect	13.0K	$18.14	$235.8K	13.0K
May 4, 2026Form 4	ARCH Venture Partners XII, L.P. +6TenPercentOwner	BuyCommon Stock · indirect	1.10M	$18.00	$19.80M	6.29M

Review ownership filings at SEC.gov ↗

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Seaport Therapeutics, Inc. (SPTX)

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