BUZZ — UK'S Big Yellow gains after activist Ancora urges strategic review, including potential sale
* British self-storage company Big Yellow Group rises 3.9% to 830.5p, highest one-day gain since 24 June * Activist investor Ancora, which owns more than 4% of the company, has urged Big Yellow to pursue a strategic review, including a potential sale * Ancora estimates the stock trades at an "unwarranted" discount to n