Teradyne Inc.’s first-quarter financial guidance fell short of Wall Street projections, sending shares down nearly 20% in after-hours trading to $115.03.

The company projected 71 cents to 93 cents a share in first-quarter profit, or 76 cents to 98 cents a share on an adjusted basis, on $700 million to $770 million in revenue. That compares with analysts’ projected profit of $1.23 a share, or $1.30 a share as adjusted, on $878.2 million in revenue, according to FactSet.