Hyperliquid co-founder Jeff Yan has defended the use of fully transparent order books, arguing that they represent the pinnacle of transaction efficiency. In a detailed article, Yan addressed criticisms regarding the suitability of transparent order books for large transactions, describing the design as both controversial and forward-looking. He outlined four key market structure principles: rejecting the notion that privacy equates to execution advantage, highlighting competition's role in enhancing transaction quality, advocating for repeated games to optimize behavior, and asserting that system-level transparency ensures information symmetry. Yan claims that Hyperliquid's use of L4 transparent order books and cancellation priority mechanisms has improved transaction quality and effectively filters toxic traffic, challenging traditional OTC and dark pool practices.