Starbucks Corp. SBUX, -2.07% said Friday it has entered an accelerated $5 billion share buyback with the help of two financial institutions, as part of its plan to return $25 billion to shareholders via buybacks and dividends through fiscal 2020. The coffee shop chain said it is using the proceeds from two recently completed transactions with Nestlé S.A NESN, -0.89% to fund the accelerated program, which is expected to be completed by Feb. 2019. Shares rose 2.1% in premarket trade, but are down 4.5% in 2018, while the S&P 500 SPX, -1.11% has gained 2.1%.