BlackBerry Ltd.’s big earnings miss and lower forward guidance has the shares tumbling almost 19 per cent to a four-year low early Tuesday.

BlackBerry’s Internet-of-Things (IoT) division and Cylance cyber security unit both missed consensus estimates and contributed to the miss, according to analysts. Shares of the Waterloo, Ontario-based company fell the most since Jan. 2015 to the lowest since Oct. 2015 on a full day’s worth of volume in the first five minutes of U.S. trading.

 RBC analyst Paul Treiber said the company’s IP revenue was “well above” RBC and Street estimates, but “strong IP licensing revenue doesn’t offset IoT and Cylance shortfall”. Raymond James analyst Steven Li agreed and said that BlackBerry’s enterprise software group “significantly underperformed” during its fiscal second quarter.

The company’s shares also tumbled during last quarter’s earnings results as sales from software and services slowed and a recent acquisition contributed less of a boost than some analysts expected.