The reason behind the market's surge has been identified, and it involves a monkey.

Today's trading session presented a complex picture for investors. While the major indices closed in negative territory, individual stocks showed strength with more gainers than decliners. The pharmaceutical sector experienced a significant rally, driven by an unusual catalyst.

On July 15th, the market experienced a day of fluctuating adjustments. The STAR 50 index fell by over 4%. At the close, the Shanghai Composite Index was down 0.29%, the Shenzhen Component Index declined 0.97%, and the ChiNext Index dropped 1.21%.

A total of 3,351 stocks advanced, with 74 hitting their daily upside limit, while 2,098 stocks declined.

Pharmaceutical stocks defied the broader market trend, moving higher. Shares including JOINN and others surged by the daily limit. The catalyst was an announcement from JOINN, which projected its first-half 2026 revenue to be between approximately 6.69 billion and 7.39 billion yuan, representing a year-over-year increase of 0% to 10.5%. More notably, the company forecasted net profit attributable to shareholders of about 6 billion to 9 billion yuan, a staggering year-over-year increase of roughly 884.9% to 1377.4%. This dramatic profit surge is primarily attributed to rising prices for laboratory monkeys. JOINN is a leading domestic player in non-clinical CRO for pharmaceuticals and possesses substantial resources of these test animals.

Driven by growing demand and constrained supply, the price of laboratory monkeys has seen a notable increase in recent years. Market information indicates that prices for some monkeys have approached 200,000 yuan each, with the tight supply-demand situation not yet fully resolved.

From an industrial perspective, laboratory animals represent an upstream foundational resource for innovative drug R&D. This segment shares similarities with parts of the tech supply chain, such as memory chips and optical modules: downstream demand is expanding rapidly, while upstream expansion cycles are long, making it difficult to quickly increase supply. This ultimately leads to price increases, enhancing the profit potential and asset value of related companies.

Stimulated by JOINN's earnings forecast, market capital began flowing into the laboratory animal sector and its related industrial chain. Some investors have even playfully dubbed this thematic concept the "monkey module."

In a more abstract development, some online commentators joked about tracing the monkey supply chain upstream to a core material—bananas. Following this narrative, shares of a company involved in fruit and vegetables trading surged by the daily limit.

Consumer stocks, such as those in the baijiu sector, also saw gains, with several companies hitting their daily price limits.

On the downside, semiconductor and chip stocks faced selling pressure, with several companies falling by their daily limit or dropping over 10%.