For investors, returns are one thing. Feeling right is second.

• Investor disagreement can push prices because market moves also validate identity.

• When people feel right, their belief can grow faster than the evidence.

• Generic nudges do not work well when people are strongly attached to their existing view.

You can see this in daily life long before you see it in a market chart. Someone believes a false story online and then starts treating every new detail as proof they were right. In investing, that process gets stronger because the feedback arrives in numbers.

A 2026 paper by Xuejun Jin and Zhenzi Tian looks closely at that pattern. Using posts from EastMoney Guba, a major Chinese investor forum, the authors study how disagreement among investors shapes later stock returns. Their dataset is huge: 241 million posts about 5,059 A-share companies, later filtered to 219 million posts from about 2.36 million investors.

The key thought revolves around self-attribution bias. When a stock rises, investors who were already bullish are more likely to treat that move as evidence of their own skill. When a stock falls, bearish investors can do the same. The paper argues that price moves strengthen identity in addition to just validating their beliefs. In the authors’ words, rising prices amplify the sentiment of initially optimistic investors, while falling prices amplify the sentiment of initially pessimistic investors.

When investors already strongly disagree, price moves have a bigger effect. A rise makes one side feel more confident, and a fall does the same for the other side. The study found that this led to bigger changes in how investors felt about the stock and stronger short term price moves. Later, prices often moved back as the market corrected. The authors see this as temporary mispricing driven by investor mood, not just fundamentals.

That is the important part of behavioral interventions: investors don’t always make impulsive decisions randomly. Sometimes they are attached to a position because the position now says something about them. A generic reminder to “stay rational” does very little once the trade has become part of the person’s self-image.

How does IRIS X help in situations like this?

It starts by building a picture of the individual, including psychological patterns and financial biases. That makes it possible to respond to the real barrier instead of giving the same advice to everyone. In a case like this, the barrier is often attachment to being right. Any useful intervention has to take that into account.

In markets, disagreement is fuel for ego and prices move with it.

Source: Jin, X., & Tian, Z. (2026). Online investor disagreement, self-attribution bias, and future stock returns. Financial Innovation, 12, Article 57. Published February 4, 2026.