$VDSI is one of biggest losers #stocks today. read more:

VASCO Data Security Internation (symbol: VDSI) was one of the worst losers
of the trading day today (2015-07-29), losing -22.98%. The number of shares
that changed hands was 6,860,970, or about 4 times the average daily volume
in the stock.
The closing price was $20.45, amounting to a market cap of $808,330,000,
about -41.57% off the highest price in the last 12 months. The stock has
been trading at a range between $13.26 and $35.0.
VDSI is in the EDP Services industry, part of the Technology sector.
Looking at its valuation, the stock is now trading at 18.56 times earnings.