Symantec (NASDAQ:SYMC) is one of the biggest players in the enterprise storage software market where it competes primarily with EMC (NYSE:EMC), IBM (NYSE:IBM), NetApp (NASDAQ:NTAP) and HP (NYSE:HPQ). According to IDC research while the storage software market expanded in the last quarter, some of the top players like Symantec have lost market share. Symantec’s market share in Q3 2011 dropped to 15.3% while EMC’s improved marginally to 24.5%. IBM’s market share increased to 14%. 
We have revised our estimates and growth forecasts to indicate that Symantec will have 16% market share in storage software for the whole of 2011. We estimate that Symantec’s market share in storage software will increase marginally going forward. If Symantec continues to show a decline in its market share and drops to 14% by the end of the forecast period, there could be a downside of about 5% to our $21 Trefis price estimate for Symantec.
Storage software is Symantec’s most valuable business, and accounts for more than 35% of its $21 Trefis price estimate, which stands nearly 20% above its current market price.Notes: