This quarter · released September 3

Only Qwen's model learns to buy cheaper; Qwen built the test

Alibaba's Qwen team and Taobao/Tmall publish E-Commerce Bench, in which 18 models each run a simulated online shop for a year. Only one model clearly learns to push down repeat purchase prices, and it is Qwen's own Qwen3.8-Max-Preview. GPT-5.6 Sol finishes first on year-end assets but ranks 16th on fraud defense. Each model starts with RMB 100,000 and runs five times. Year-end assets: GPT-5.6 Sol RMB 1.43M, against an average of only RMB 1,100 for Qwen3.5-Plus. On fraud, the share of purchases flowing to fraudulent suppliers is 0.12% for Claude Opus 4.7 and 20.11% for Qwen3.5-Plus, against a no-screening baseline of 26.4%. The share of orders placed with a fraudulent supplier already contacted is 31.7% for GPT-5.6 Sol and 4.0% for Claude Opus 4.7. The learning metric, AnchorRatio, measures whether repeat purchases of the same item from the same supplier get cheaper over time: 1.0 is no better than random, and below 1.0 means buying cheaper. The blog says: "Over a full year, the models do not get better at buying. Qwen3.8-Max-Preview is the only one of the 18 showing a clear sign of long-horizon learning, at an AnchorRatio of 0.834" (Qwen blog, 2026-09-03). Qwen3.5-Plus and Qwen3.8-Max-Preview come from the same company, and Qwen3.8-Max-Preview is the only one of the 18 that learns. This is Qwen's own benchmark, the only model that learns is Qwen's, and the paper and code haven't been reviewed. Our reading: judging long-horizon agents on total assets alone misses two failure modes, fraud defense and learning. How we checked →

Concept illustration: a long brick-red counter runs diagonally from the left foreground into the distance, holding a row of six open laptops whose screens show small icons of a T-shirt, a shoe, a mug, a chair and a shopping cart plus a box of grey lines, with a tall black sign lettered E-COMMERCE BENCH standing at the left. A person with dark curly hair, a black turtleneck, wide beige trousers and a lanyard badge stands at the counter looking at the laptops, one hand resting on the counter and the other in a pocket, in front of a pale pink circle on the wall, while a black sign at upper right is lettered ALIBABA QWEN beside an orange curved mark.

Source and checks

This item ran in the brief of Oct 16, 2026, alongside 19 other items. How we checked it, the quote checks and what was still missing that day are on that issue's How we checked page.

Cite this item

SecondSource (2026). "Only Qwen's model learns to buy cheaper; Qwen built the test." https://secondsource.io/en/research/2026-10-16-1/. Accessed access date.