While Moody's Investor Service said that it has had higher credit enhancement levels for negative amortization loans for a number of years, analysts from the rating agency acknowledge that there has been a considerable increase in securitizations backed by these loans, with a substantial pick-up starting last year. "We've been making a 15% to 20% adjustment for neg ams for a few years," Daniel Gringauz, a vice president at Moody's said. "We've always viewed neg am loans more harshly." The key difference in these loans is the lack of equity build-up together with the fact that the principal balance of neg am loans can actually increase, thus potentially resulting in the reduction of the equity in the borrower's property.