Image Source: InvenSense.

What: Shares of InvenSense (INVN), a provider of sensors found in consumer electronics, fell 19.5% in May, according to data provided by S&P Global Market Intelligence. The company suffered a major revenue decline during its fiscal fourth quarter due, in part, to weak iPhone sales.  

So what: InvenSense reported quarterly revenue of $79.5 million, down 20% year over year, and just shy of the average analyst estimate. InvenSense's two-largest customers, which includes Apple, accounted for 53% of revenue during the fourth quarter. Apple reported its first-ever iPhone sales decline in April, along with disappointing guidance -- news that weighed on the shares of major suppliers.

Non-GAAP (generally accepted accounting principles) EPS came in at $0.02, down from $0.12 during the prior-year period, and in line with analyst expectations. On a GAAP basis, the company posted a $0.25 per-share loss compared to breakeven during the same period last year. Lower revenue and higher operating expenses were responsible for the steep drop in earnings.

According to the company's guidance, the bad times are set to continue. InvenSense expects first-quarter revenue between $58 million and $62 million, well below analyst estimates of $84.8 million. A non-GAAP EPS loss between $0.05 and $0.07 is expected compared to analyst expectations of a $0.04 profit.

Now what: InvenSense CEO Behrooz Abdi expects that the Internet of Things will help drive growth going forward, despite weakness in smartphones. "Our market-leading solutions continued to gain traction in emerging Internet of Things (IoT) platforms such as drones, virtual and augmented reality, wearables, smart home, and industrial applications. We believe that the broad applicability of our portfolio positions us for continued diversification and growth in these exciting markets."

With InvenSense heavily dependent on the smartphone market, in general, and on Apple, in particular, the company's results may not rebound anytime soon. The smartphone market has slowed down, and the launch of a new iPhone later this year may not produce the typical boost. Consumers are holding onto phones for longer periods of time, with year-to-year improvements no longer meaningful enough to drive upgrades.

The growth story at InvenSense is on hiatus, which led investors to send the stock tumbling in May.