Abstract
Emerging markets efficiency has been widely investigated, with mixed results. However such evidence is only reliable if the methodology adopted accounts for the institutional features of the market. Unlike previous studies this paper corrects for thin trading and incorporates possible non‐linear behaviour and regulatory changes. Using Istanbul Stock Exchange data we show that in its early years the exchange was characterised by non‐linear behaviour and inefficient pricing. However, regulatory changes encouraged participation, improved information quality and led to prices impounding information more rapidly, suggesting markets become efficient with high trading volume, reliable information and an appropriate institutional framework.