Amid the surge in obesity drug development, experts are uncertain about the effectiveness of weight loss ETFs.

Investing in single stocks may be a better option than exchange-traded funds in the weight loss industry.

Last week, both Amplify ETFs and Roundhill Investments submitted prospectuses to launch funds concentrating on weight loss companies. According to Strategas ETF and technical strategist Todd Sohn, the success of these funds is contingent on the performance of two prominent stocks: and .

"The major holdings will likely be Lilly and Novo Nordisk, along with a few other big names, as well as some manufacturers further down the supply chain," he stated on CNBC's "ETF Edge" this week. "In the end, it's the big players in the pharmaceutical industry who will have the most significant impact."

Simeon Hyman of ProShares questions the relevance of weight loss ETFs for investors in the U.S. obesity drug market, with only two players currently leading the market.

"The global investment strategist of the firm stated in the interview that one of the challenges of seeing an innovation like this is that if the benefits are going to incumbents, then perhaps there isn't a specific theme that needs to be exploited."

ETFs based on themes, rather than sectors or indices, may be losing popularity among investors, according to Strategas' Sohn.

He stated that thematics are currently being pushed to the backburner, particularly due to their poor performance in the past couple of years. While there is still some room for them, he believes it will be challenging to have more than one of them.

As of Wednesday's close, both Novo Nordisk and Eli Lilly have experienced significant growth in 2024, with Novo Nordisk gaining 29% and Eli Lilly up 30%. The broader market has also risen by 7% during the same period.