What would cause a stock to be sold at different prices in different markets according to arbitrage principles?

The phenomenon of a stock being sold at different prices in different markets can be attributed to temporary market inefficiencies. In an efficient market, the same asset would generally have the same price across various trading platforms due to the actions of arbitrageurs who exploit pricing discrepancies. However, temporary market inefficiencies can occur due to various factors such as delays in information dissemination, differences in trading volumes, or even technology lags between exchanges. During these inefficiencies, the same stock may be available at different prices until arbitrageurs step in to buy the undervalued stock and sell the overvalued one, thus correcting the price discrepancy.

The other factors listed—such as lack of investor interest, regulatory restrictions, and increases in interest rates—pertain to different market dynamics and do not directly explain the occurrence of price discrepancies across markets in the way that temporary market inefficiencies do. These other factors could potentially influence pricing indirectly but are not the primary reason for the existence of differing stock prices across markets based on arbitrage principles.