Starbucks missed earnings and revenue estimates for its fiscal second quarter. Same-store sales fell for the fifth straight quarter. Still, CEO Brian Niccol said the coffee chain is seeing "momentum" in its turnaround,

Starbucks faces challenges in reviving its business, CEO Brian Niccol said on Tuesday, after the coffee giant posted disappointing global comparable sales and profit with inflation and economic uncertainty driving up costs and dampening U.

But those efforts have been costly. Starbucks said its net income dropped 50% to $384 million in its fiscal second quarter. Adjusted earnings fell nearly 40% to 41 cents per share. That was lower than the 49-cent per share profit Wall Street forecast.