The size of the debenture pool of unlisted debt market may be on the wane, in the wake of the collapse of a number of property development financiers and increasing regulatory attention from ASIC.A pair of follow up reports on the sector published last week by ASIC provides an updated snapshot of the market, as well as a profile of investors attracted to unsecured notes and debentures.In one report ASIC estimated the "unlisted and unrated debenture" segment at $6.7 billion, which is down from an estimate a year ago of around $8 billion."Debt funding" and "mortgage financing" accounted for the vast majority of this sector, with aggregate funds invested of $2.7 billion each."Finance" accounted for $911 million, "structured real estate" $330 million and "memberships" $108 million.ASIC compiled a fresh list of 82 issuers of unlisted and unrated debentures as at March 2008.The regulator has even published a list of disclosure documents by each issuer at a dedicated page at the ASIC website, with links to the ASIC copy of the document for each borrower.In one measure of the changes in the sector, ASIC now lists 31 issuers of debentures in the mortgage financing category, down from 36 in August 2007."Debt capital funding" issues decreased four over the same period to 17, with "structured real estate investments" shedding one to nine in total."Memberships", (debentures issued to facilitate membership of clubs, groups or franchise operations), were unchanged for the period at seven, "integrated property" decreased one to two, with "finance" increasing one to sixteen.