Bowdoin College (ME) posted a 15.7 percent investment gain, the highest one-year performance among the richest schools including much larger Ivy League endowments.  The value of the fund was a record $1.6 billion at June 30, the liberal arts school in Maine said Tuesday in a statement. Some elite schools including Bowdoin have reported double-digit gains in fiscal 2018 driven by strong private equity and venture capital returns.