I'm investing in the stock market

October 8, 2026 · biology, finance

Epistemic status: biology linked, thesis plausible, financial plan deranged. See footnotes.

Who wouldn't want to look like Arnold Schwarzenegger? Man's fkn massive and lean and operating at the limits of the aesthetic, a body less grown than quarried. The issue w/ looking like this is that it usually requires a sacrifice: you have to inject yourself with anabolic androgenic steroids. The most common of which is testosterone, the bioidentical hormone responsible for many downstream functions of the male human body, one of which is muscle growth. There are other injectable or ingestible compounds which emulate the effects of testosterone to different degrees, some w/ more extreme effects in certain ways and less in others. A whole pharmacopeia of synthetic cousins, each one a different trade between how much it builds and how much it breaks.

The side effects of steroids are usually the problem. Even if you didn't care about the health effects, they may have negative effects on your appearance, which is presumably the reason you took them in the first place. For example, the conversion of this exogenous testosterone into DHT may cause you to start balding at an earlier age, or suddenly start having acne as though you were a teenager again (MSD Manual lists acne and alopecia right next to each other, as if your body decided to relive adolescence and middle age at the same time). A Faustian bargain in which the devil also takes your hairline.

Injecting yourself w/ exogenous hormones also has, in hindsight, a very obvious effect: the organs responsible for producing them stop receiving the signal to produce more. In the case of testosterone, the testes shrink and may ultimately atrophy, leaving you w/o the ability to have offspring. A 2017 meta-analysis of ~3,900 people found most users had hypogonadism w/ persistently low testosterone, often lingering after they stopped.¹ There are ways to get around this, for example injecting HCG, the hormone that tells the testes to keep working. But you may ultimately just be pushing the problem further and further down the chain. A hormonal Ponzi scheme where every fix needs its own fix.

Peptides are a new class of drugs that are not quite like steroids. They seem to come w/ few side effects, and even the side effects sometimes seem good. For example, it has been found that some users seem to lose their addictive cravings: in a 2025 randomized trial in JAMA Psychiatry, low-dose semaglutide reduced how much people w/ alcohol use disorder drank and how much they craved it, and the smokers cut back on cigarettes too. A drug for being fat that also makes you want less of everything. Squint and it looks less like a pharmaceutical than a theology.

It is, in some sense, a miraculous class of drugs. They were discovered, are now widely used, unlocked general health benefits, and of course, made lots of money for the pharma companies, now reflected in their valuations. Tirzepatide passed Keytruda as the world's best-selling prescription drug in 2025, and Eli Lilly briefly became the first drugmaker ever worth $1 trillion, on a stock up more than 10x since 2018.² For the most part, effective peptides have so far existed only in the form of weight-loss drugs, which of course many Americans want. But what if there was a steroid peptide?

Myostatin is the hormone responsible for stopping muscle growth.³ That's right, your body naturally always wants to produce more muscle, but it must be stopped because otherwise it would starve itself of resources required for other bodily functions. We know what happens when the brake comes off because of cows: in 1997, McPherron and Lee showed that Belgian Blue cattle carry a deletion in the myostatin gene that wipes out nearly all of the active protein. Look one up. It's a cow drawn by someone who'd only ever had cows described to them by a bodybuilder.

There are now drugs that are myostatin inhibitors. Apitegromab by $SRRK is one of them, and as of last month it's FDA-approved (as Isembyld, for spinal muscular atrophy), the first win after decades of failed attempts at myostatin inhibition. Regeneron has trevogrumab, and Lilly paid up to $1.925B for bimagrumab in 2023. That's right, you can get jacked w/o all the negative side effects that come w/ injecting exogenous hormones.⁴

And they don't even need the "let me be jacked" argument to get approved, because they're coming in through the side door. About 30% of the weight lost on tirzepatide and 33% on semaglutide is lean mass, not fat. Add apitegromab and you keep 54.9% of that muscle. In Lilly's BELIEVE trial, bimagrumab alone added 2.5% lean mass while people lost weight. "Preserve muscle during obesity treatment" is an indication. Off-label, compounding pharmacies and podcasts take it from there.

A new world is coming. In the same way that the weight-loss peptides took the world by storm, it is my belief that as these drugs become safer and cheaper, we will talk about them the same way we talk about Ozempic today. Just 5 or 6 years ago semaglutide, and later retatrutide, were only talked about in biohacking circles, alongside MK-677 and SARMs, w/ Derek from More Plates More Dates or Leo and Longevity. Since then the pharma companies have added hundreds of billions to their market caps.

The muscle drugs come w/ their own challenges of course, in that the regulatory argument (that adults should be able to use it 🫩) is weaker. Regardless, human desire tends to win, in one way or another. And so I'm levering myself, all the way up. I'm riding the muscle peptides to a billion dollars by betting everything I have, borrowing everything I can, and investing it in the companies that will be responsible for deploying them.⁵