Looking for investing ideas with the backing of sophisticated investors? Here we give you just that. The stocks listed below have met the following criteria:

Short covering
Shorting a share involves borrowing the share and immediately selling it with the agreement to buy it back and return it in the future. This is profitable only if the share price drops, in which case the short-seller gets to keep the difference in value (minus a borrowing fee).

Thus, heavy short-selling indicates a bearish (or pessimistic) view on the stock's prospects. And a pullback on shorted shares means these traders are becoming more optimistic about the stock's near-term values.

Below we list names that have seen a significant decrease in shares shorted month over month -- a sign these sellers think there is more upside potential than not.

The "overweight" rating
We then screened our list for stocks Barclays, a major global financial services provider, is feeling very bullish about and has given "overweight" ratings.

Big financial firms, though certainly not always correct, put a lot of analysis into their ratings. So we can assume they have good reason for rating a company "overweight" – the highest bull rating available (versus "equal weight" or "underweight").

Business section: investing ideas
Do you think Barclays and short-sellers are correct to feel optimistic about these names? Do you think the market is undervaluing these names? Use this list as a starting point for your own analysis. (Click here to access free, interactive tools to analyze these ideas.)

1. GOL Linhas A (NYSE: GOL) operates as a low-cost, low-fare airline in Latin America. It has a market cap of $1.41 billion, with a most recent closing price of $5.23. On Nov. 1, 2011, Barclays Capital had an overweight rating on the stock. Shares shorted have decreased from 9.92 million to 7.97 million over the last month, a decrease which represents about 2.17% of the company's float of 89.72 million shares. The days-to-cover ratio stands at 4.62 days.

2. Lennar (NYSE: LEN) operates as a homebuilder and provider of financial services in the U.S. Its market cap is $5.38 billion, with a most recent closing price of $28.45. On Oct. 13, 2011, Barclays Capital had an overweight rating on the stock. Shares shorted have decreased from 32.51 million to 30.17 million over the last month, a decrease which represents about 1.44% of the company's float of 162.4 million shares. The days-to-cover ratio is 4.63 days.

3. OpenTable (Nasdaq: OPEN) provides restaurant reservation solutions in the U.S., Canada, Mexico, Europe, and Asia. With a market cap of $841.18 million, its stock most recently closed at $37.27. On Jan. 9, 2012, Barclays Capital had an overweight rating on the stock. Shares shorted have decreased from 8.76 million to 8.53 million over the last month, a decrease which represents about 1.35% of the company's float of 17.06 million shares. The days-to-cover ratio is 8.88 days.

4. Tesla Motors (Nasdaq: TSLA) designs, develops, manufactures, and sells electric vehicles and advanced electric-vehicle powertrain components. It has a market cap of $3.39 billion, with a most recent closing price of $32.25. On Nov. 11, 2011, Barclays Capital had an overweight rating on the stock. Shares shorted have decreased from 24.24 million to 23.53 million over the last month, a decrease which represents about 1.03% of the company's float of 68.7 million shares. The days-to-cover ratio stands at 19.26 days.

5. Tesoro (NYSE: TSO) refines and markets petroleum products in the U.S. With a market cap of $3.15 billion, its stock most recently closed at $22.46. On July 6, 2011, Barclays Capital had an overweight rating on the stock. Shares shorted have decreased from 9.32 million to 7.54 million over the last month, a decrease which represents about 1.28% of the company's float of 138.88 million shares. The days-to-cover ratio is 1.91 days.

Interactive Chart: Press play to compare changes in analyst ratings over the last two years for the stocks mentioned above. Analyst ratings sourced from Zacks Investment Research.