A closer gap in these prices means more trading volume for the stock. (investopedia.com)
Petroneft, like most Irish resource stocks, has far more trading volume in London vs. Dublin — generally, a higher volume market should offer better spreads / prices... but not always! (wexboy.wordpress.com)
Data from Bitcoinity shows more trade volume during the past several hours than at any other point during the past week. (coindesk.com)