Madrigal Pharmaceuticals (MDGL 3.36%) and Viking Therapeutics (VKTX 0.98%) are both biotechs developing treatments for metabolic diseases, so it's to be expected that they have more than a few things in common. But investors are probably interested most in the fact that shares of both companies are soaring over the last six months.

Will one of the pair fly higher than the other? Let's look at each to develop an idea about which of these booming biotechs is going to be the better bet.

Madrigal's boom is well underway

With the approval of Madrigal's medicine by the Food and Drug Administration (FDA) on March 14, the biotech made history by developing the first therapy to treat metabolic dysfunction-associated steatohepatitis (MASH, formerly known as NASH).

The drug, called Rezdiffra, will officially launch in April, and it'll be the first opportunity that the company has had to generate revenue. Management estimates that around 315,000 people in the U.S. will be eligible for treatment for now, though with additional research and development (R&D), it may be possible to expand the eligible patient population to more than 1.5 million people.

Such a long runway for expanding its indications to capture more growth is highly bullish as it implies that one product could yield revenue for many years to come. And Madrigal has the entire market to itself, at least until a competitor can get a competing therapy approved.

Regulators in the E.U. are already considering the approval application to commercialize Rezdiffra, so its addressable market is in all likelihood going to increase quite soon. Madrigal won't have any trouble penetrating its market, either. Thanks to a new stock offering on March 18 that's expected to be worth a total of $600 million in gross proceeds, it will have more than enough cash to spin up its manufacturing and distribution capacities to meet new demand, not to mention paying an expanding roster of C-suite executives.

In sum, Madrigal's years of hard work in the laboratory and clinical trials is about to start paying off big time. Investors who buy the stock now are at a low risk of getting their shares diluted, and they'll also get the benefit of its soon-to-begin growth as well.

Viking's stock is climbing, but key risks remain

Viking Therapeutics doesn't yet have a medicine approved for sale, but it does have some solid data in hand from one of its phase 2 trials, which suggests that it could produce a powerful weight loss drug within the next few years.

Getting a treatment for obesity on the market would grant the biotech access to one of the largest pharmaceutical markets that exists, if not the largest. While it would need to battle against entrenched and gargantuan competitors like Novo Nordisk and Eli Lilly, there is already so much demand on the market that neither of the reigning leaders can manufacture their medicines fast enough at present.

Such conditions are unlikely to last for the long term. But it probably only needs to spend a couple of additional years in clinical trials before it has its shot at regulatory review. Thus, it is most likely the case that Viking has a shot to get a share of the market while the getting is still good.

Its odds look even better when considering that it won't be experiencing severe financial constraints right away. Viking just closed a public stock offering on March 4, with gross proceeds of $632.5 million. With its trailing-12-month total expenses coming in at $100.8 million, it almost certainly has enough money from the offering alone for it to get its lead candidate out the door over the next few years.

Of course, there is still the very real risk that its clinical trials could go awry, but at present that risk does not appear to be very large. So if you're the betting type, it's fair to bet on its candidate eventually being commercialized.

Viking also has a promising program for MASH in phase 2 trials, but if it ever reaches the market, it'll need to pry its share away from Madrigal, which could be a difficult slog given the lead Madrigal has.

There's a clear winner, but neither option is bad

Both of these biotechs appear on track to succeed over the coming years. Nonetheless, Madrigal has a drug in hand that will soon yield sales, and Viking does not. While Viking's top line will almost certainly be much larger if it ultimately gets its weight loss therapy approved, the approval isn't a sure thing, and the competitive factor could be an issue.

Therefore, Madrigal is the better booming biotech stock at the moment. Don't be afraid to buy shares of both companies, though. While there is indeed some overlap of their target markets, the chances of their fighting each other directly are minimal because of the timing, and larger competitors are more important concerns anyway.