NEW YORK ( TheStreet) -- The estate of the Wal-Mart ( WMT) Walton family is again selling shares of First Solar ( FSLR). In a recent transaction reported late on Tuesday, the estate of John Walton sold two batches of more than 33,000 shares of First Solar at a price of $140. First Solar hit the $140 share price on July 23. The proceeds from the Walton's First Solar sale was more than $4.6 million in each of the two sales, according to insider selling information on the web site InsiderInsights.com. In May, the Walton estate last sold First Solar shares, in range in between $140 and $148 in a much bigger set of insider transactions. The more recent First Solar share sale was relatively small as compared to the selling in May, when the Walton estate shed more than 300,000 shares of First Solar. In any event, First Solar watchers are always interested in the times and at what share price the Waltons -- early financial backers of First Solar and the U.S. alternative energy sector generally -- decide to shed the U.S. solar stock. First Solar is expected to report strong earnings on Thursday. However, there are concerns that the current strong demand levels in solar won't last in 2011. Nevertheless, several analysts have price targets on First Solar much higher than its current share price near $137. Jefferies recently initiated coverage of the solar sectors with a recommendation to wait for a better time to buy into U.S. solar stocks, including First Solar. -- Written by Eric Rosenbaum from New York.