Only Italy performed worse in the period. The main main stock market index in the country went up by 42% in the five-year period, or 7% a year.
The stock markets in the 27 EU member countries rose by an average of 118% over the past five years, or 17% a year.
Eastern Europe accounted for eight of the 10 EU countries with largest growth in stock prices since 2003.
Bulgaria toped the ranking with growth of 352% during the past five years, which represents an increase of more than six times compared to the growth of British stock prices.
Bulgaria is followed by Lithuania (309%), Romania (299%), Luxembourg (263%) and Austria (247%). Poland, the Czhech republic, Hungary, Slovakia and Estonia rounded out the top 10.