Big hedge fund managers such as David Einhorn and Bill Ackman get much of the attention, but there are under-the-radar stars that are performing even better.

Who are these top stock pickers and what stocks are they buying?

CNBC used Symmetric.io, a hedge fund tracking firm, to find the best under-the-radar managers and which stocks they recently bought according to filings.

Four times a year, hedge funds file their long positions with the SEC and the information is released to the public 45 days after each quarter ends.

With the recently released June quarter filing data, Symmetric.io graded the stock-picking ability of more than 1,000 hedge funds in its database with a proprietary indicator called StockAlpha. It is derived by comparing the performance of equities in the fund to that of a sector ETF.

Here are the top 10 stock-picking hedge funds measured by StockAlpha, many of them run by managers you’ve likely never heard of.

Some investors focus on where funds started a new position as it may mean the manager believes it offers the best current opportunity.

Here are some new stock additions from the top 10 stock pickers.

Financials stocks were a big area of focus in the June quarter for the best stock picking hedge funds.

In similar fashion, Warren Buffett also added to his banking sector investments in the second quarter.