We exploit the rich data of business groups in China and identify sell-side analysts following multiple listed firms within a business group (BG analysts). For a group firm, we find that BG analysts issue more accurate forecasts than non-BG analysts. Such an effect is more pronounced when the focal firm shares stronger economic links with, and when its covering analysts have greater information demand for, its group peers. Further analyses suggest evidence of intragroup information flows. Around group peers’ annual earnings announcements, BG analysts are more likely than non-BG analysts to revise their forecasts for the focal firm along the same direction as group peers’ earnings surprises. Confined to analysts’ coverage initiations for a group firm, those who have covered the focal firm’s group peers prior to the coverage initiation show superior forecasting performance during the initiation year. By adopting the unique perspective of business groups, i.e., a prevalent organizational structure, our study shows that information commonalities within a business group shape analyst behaviour.