The highest return among stocks in the Standard & Poor’s 500 index for the year so far is Pulte Homes, the major homebuilder; as of Wednesday morning it had returned investors 195 percent. No. 6 on the list is Lennar Corp., a Pulte competitor. S&P’s overall index for the homebuilding industry is up 59.4 percent this year, and across the homebuilding industry, sentiment rose to its highest level since the middle of 2006, the National Association of Homebuilders said Tuesday.