Business

BlackBerry goes sour

BlackBerry shares tumbled yesterday for a second straight day after Goldman Sachs cut its rating on the struggling smartphone maker, citing a disappointing debut for the company’s Z10 phone in the US.

The shares fell 4.6 percent, to $14.23, following a decline of 7.7 percent on Friday. Before the two-day drop, the stock had climbed 36 percent this year.