George Soros purchased more than 1.8 million shares of Exar Corp. last week, at prices between $5.59 and $5.71. The first transaction, made on September 21st, was reported to the SEC less than a minute before the legal deadline, on September 23^rd at 9:59 pm. This indicates that Soros did not want to reveal his trades until he had to. The total dollar value of the purchases was $10.5 million. Soros has a total of 6.27 million EXAR shares, which is more than 10% of the outstanding shares. EXAR closed at $5.59 on September 23^rd, yet it opened at $5.75 the next day. This example shows the challenges of imitating insider transactions, especially in small companies. The insider trading news caused the stock to jump nearly 3%. Overall, stocks show significant positive excess returns for the 5 days following an insider purchase.   EXAR was trading around $7 per share during July and slid around 20% to $5.60. Soros might have thought that the stock got cheap enough and decided to increase his holdings by around 20%. Exar  is a fabless semiconductor company that designs, sub-contracts manufacturing and sells highly differentiated silicon, software and subsystem solutions for industrial, telecom, networking and storage applications. Their core expertise in silicon integration, system architecture and software has enabled the development of innovative solutions designed to meet the needs of the evolving connected world. Their product portfolio includes power management and interface components, datacom products, storage optimization solutions, network security and applied service processors. Applying both analog and digital technologies, their products are deployed in a wide array of applications such as portable electronic devices, set top boxes, digital video recorders, telecommunication systems, servers, enterprise storage systems and industrial automation equipment. They provide customers with a breadth of component products and subsystem solutions based on advanced silicon integration. Exar was incorporated in California in 1971 and reincorporated in Delaware in 1991.