
Shares of Citigroup climb as much as 3.6% to $90.68, hitting their highest since 2008
Bank's Q2 profit exceeded Wall Street estimates, thanks to strength in its investment banking and trading divisions
"We're very pleased on the M&A front — the pipeline is excellent," CEO Jane Fraser says
Citi would repurchase at least $4 billion of stock in the current quarter, bank says
Stock has gained nearly 28% YTD