Vest launched funded accounts on Nov 3, 2025 and since then they have maintained the stance that they are the first fully A book prop firm. Today I asked Vest support directly. Have you always been a fully A book prop firm, with funded trades on the real exchange? "Yes." In Justin's article he posted today, he defines A book as the firm routing orders to a real market where they "fill against other participants," earning "not from clients losing." B book is when the firm "takes the other side itself." Now here's what Vest's own admins said in Vest's own Discord while those funded accounts were live. January: "the internal MM is the only counter party to these assets most of the time." That's why they cap open interest on their stock markets. This month, asked who the liquidity provider for NQ is: "We provide our own liquidity, as we are an exchange." A firm that provides its own liquidity, with an internal MM as the only counterparty, "takes the other side itself." By Justin's own definition, that's B book. The A book claim is a lie. And Vest knows it. Look at the Prop Terms, updated Oct 20, after weeks of Vest saying it would update the language to make things clearer. The very first line calls Vest "a simulated proprietary trading program." Every funded account, including instant funded, is "simulated" and "users do not execute live trades." It also says you can't rely on any statements "from or by us or any person acting on our behalf and including any statements made on social media, Discord, or marketing materials." "By us or any person acting on our behalf." That's Justin's article. That's the admins in Discord. That's support telling me my trades are on the real exchange. That's a cover your ass clause. Vest sells you "fully A book" everywhere it can, then the terms you actually sign say it's simulated and that nothing anyone at Vest told you counts. This shows Vest isn't A book. Their own team confirms the other side of your trade is Vest's internal MM, their own terms call it simulated, and the A book claim only exists in places their terms say you can't rely on.