Forget about subprime mortgages.

The latest toxic debt to overwhelm Wall Street hotshots is their own massive share of the nation’s $1 trillion-plus in student-loan debt. And the distressing sums owed by today’s young finance gurus are mounting fast, according to a new survey.

A mere one-third or so of finance-service professionals who graduated in the past decade left college without any debt, according to the career site eFinancialCareers’ survey. What a difference a generation makes! Between 1971 and 1982, twice as many of the finance pros finished college practically debt-free.

The debt pile and the repayment period for today’s grads are climbing, says Constance Melrose, managing director at eFinancialCareers North America,

Three out of 10 owed between $26,000 and $75,000 after graduation. That compares with a significantly smaller 6 percent of the previous generation who had a similar level of debt.

In addition, Melrose notes, more than 80 percent of the older generation retired their debt in less than five years. Yet only half of the latest class can do so, according to the eFinancialCareers survey.

These aspiring Masters of the Universe share a dubious distinction with legal eagles in training and with other seekers of coveted careers. For example, nearly half of all medical students had $100,000 or more in debt by the time they began their careers, a recent study by analyst Mark Kantrowitz reveals. He puts the nation’s explosive student-debt pile in excess of $1 trillion — enough to finance a bank bailout.

True, finance majors often start their careers earlier than professionals in medicine and other fields that require many years of difficult study.

Nevertheless, Street kids’ debt levels are just as alarming today as any of those other professionals’, analysts say.

“From entry-level jobs to those with traditionally large salaries, the burden of student-loan debt is causing grads to make more compromises than their parents [had to] in terms of delaying homeownership, putting off starting a family and moving back home with mom and dad — all while facing widespread joblessness,” said Patricia Seaman, senior director of the National Endowment for Financial Education. “Young adults know it’s hard.”