parisonr, you couldn't be more correct. CDNS is virtually always on the list of top 50 stocks short by volume.
However, try and get any information out of CDNS Investor Relations as to who is shorting this stock is an exercise in futility. It's interesting that a stock that has institutional ownership of greater than 100% (per Yahoo Finance) is on the monthly list of stocks most heavily shorted. The sad part is that you get the impression that their Investor Relations organization is either clueless or don't realize the damage shorts can do to the viability of a company.