Some of the recent 15-year supply might have served as hedges for ARM originations, said JPMorgan. The lack of a TBA market in ARMs makes hedging of pipelines harder. ARM supply is usually observed closer to the settlement date. In contrast, fixed-rate supply usually hits the market as soon as borrowers lock rates. JPMorgan explained that, as ARM originators hedge their pipelines with 15-year product, it is possible that much of the recent 15-year supply may serve only as a pipeline hedge. Thus in a few weeks, when ARM supply hits, 15-years might tighten sharply as originators buy back their hedges, said analysts. Analysts have said that the increased importance of hybrids means that investors should look into hybrids when filling intermediate buckets. One drawback is that ARMs are not part of any index.