sentences:  The ban expired on the 31 January 2010 and was not renewed at that time.On 19 May 2010, in response to 2010 European sovereign debt crisis, BaFin banned naked short selling of credit default swaps on euro-area government bonds until 31 March 2011.At the same time they re-introduced a ban on naked short selling of the previous 10 banks and insurers companies.