Cablevision Systems Corp (CVC): GAMCO Investors Trims Exposure

Page 4 of 17 – SEC Filing

CUSIP No. 12686C109

1	Names of reporting persons I.R.S. identification nos. of above persons (entities only)         Gabelli Securities, Inc.                             I.D. No.  13-3379374
2	Check the appropriate box if a member of a group (SEE INSTRUCTIONS) (a) (b)
3	Sec use only
4	Source of funds (SEE INSTRUCTIONS) 00-Client funds
5	Check box if disclosure of legal proceedings is required pursuant to items 2 (d) or 2 (e)
6	Citizenship or place of organization    Delaware
Number Of Shares Beneficially Owned By Each Reporting Person With		: 7 : : :	Sole voting power 814,180  (Item 5)
		: 8 : : :	Shared voting power None
		: 9 : : :	Sole dispositive power 814,180  (Item 5)
		:10 : : :	Shared dispositive power None
11	Aggregate amount beneficially owned by each reporting person 814,180  (Item 5)
12	Check box if the aggregate amount in row (11) excludes certain shares (SEE INSTRUCTIONS)
13	Percent of class represented by amount in row (11) 0.37%
14	Type of reporting person (SEE INSTRUCTIONS)     HC, CO, IA