The global bond market’s primary benchmark, the 10-year U.S. Treasury yield, is knocking on the door of 3 percent, a level it hasn’t topped in more than four years. That’s more than just a nice round number. Higher yields make the burden of everything from mortgages to student loans and car payments even heavier. Some market gurus see it as a turning point with effects that could be felt for years — and not just in bonds. With the Federal Reserve signaling interest rates are going up even more, investors in riskier assets like stocks and high-yield debt are left to wonder if this is how their post-recession party ends.