Any instrument executed on or after 24 December 2008 which transfers stock or marketable securities on sale where the amount or value of the consideration is €1,000 or less, is exempt from stamp duty. eBrief No. 7/09 advises that to avail of the exemption the instrument must be certified.
According to the eBrief, the Certificate must be worded as follows:
"It is hereby certified that the transaction effected by this instrument does not form part of a larger transaction or of a series of transactions in respect of which the amount or value, or the aggregate amount or value, of the consideration which is attributable to stocks or marketable securities exceeds €1,000."
eBrief No. 7/09 is available here