It’s a convoluted story Kathleen.
In a complex series of corporate deals and name changes that became final on 30 December 2016 involving the old ICAP and Tullet Prebon, two new shares emerged to replace the old ICAP, NEX Group (NXG) and TP ICAP (TCAP). So from that date if you were a former ICAP holder, you would instead have become a holder in NXG and TCAP and the old ICAP ceased to exist in its original form.
You would never as a result of these deals held shares in Tullet Prebon but the way they arranged things TCAP is actually Tullet Prebon renamed. But that fact is just a technicality having no bearing on anything.
Having sold NXG, you are left with TCAP shares as I mentioned in the article. TCAP is currently a Hold in TDL.