The omens for Commonwealth Bank's PERLS VIII hybrid, which closed last week, are not promising. Despite having the widest credit margin yet seen on additional tier one capital - 520 basis points - the notes were priced in the bookbuild at levels below those available in the secondary market for comparable issues.While the trading margins on those comparable issues, from the other major banks and the CBA itself, have since contracted slightly, the margins remain wide of the margin set on PERLS VIII. Indeed, the trading margin on the much maligned PERLS VII was 567 bps.Bank hybrid investors have had their fingers burnt too many times to continue to enthusiastically rush each new issue that comes along.  Co-manager of the issuer, Bell Potter, observed last week that the take-up of the PERLS VIII notes in the rollover offer for PERLS III holders was the lowest yet seen.Only 22.3 per cent of holders of the A$1.2 billion PERLS III notes holders opted to take up the PERLS VIII notes prior to the bookbuild. Recent issues from ANZ and Westpac have seen rollover rates of 58 per cent or more from older issues approaching their call dates.Even 66.4 per cent of PERLS IV notes holders opted to rollover into PERLS VII, which of itself may explain the poor take-up of the PERLS VIII notes by PERLS III noteholders. But PERLS III noteholders also had the experience of seeing more than 35 per cent of the face value of the notes wiped out in secondary market trading during the financial crisis.This experience would have amply demonstrated that the capital stability of hybrid notes is not much better than that of the shares of the issuer, during a time of crisis.There is also the continuing poor performance of almost all the hybrid notes issued last year to take into consideration.The ANZPF notes were issued in March last year and are currently marked on broker rate sheets at less than $90. A few weeks later the NABPC notes commenced trading and are currently marked at less than $94.In September, Westpac's WBCPF notes listed on the ASX with the widest credit margin seen until then, of 400 bps. That issue is trading in the secondary market at less than $95.Macquarie Group listed its MQGPB additional tier one capital notes at the end of last year. These notes, with a credit margin of 515 bps, now trade at less than their $100 face value.The only notes listed on the ASX last year that are trading above face value are Australian Unity's senior ranking AYUHB notes, also listed in December. The notes are marked at more than $103.The CBA PERLS VIII notes were launched as a $1.2 billion offer. The bookbuild attracted offers totalling only $910 million.The final size of the issue remains to be seen but based on the performance of the hybrid notes listed on the ASX over the past twelve months, the larger the final size of the issue the greater the likelihood that the