中國概念股（簡稱中概股）是指在海外上市的且以中國境內的資產或營收為其主體組成部分的股票的總稱。自20世紀90年代初至今，中概股登陸美國股市已有20多年。但2011年開始，中概股出現首次退市潮，除部分質量欠佳的中小企業被動退市外，一部分自由現金流較高的優質企業選擇私有化主動退市。在國外中國概念股企業價值被嚴重低估，而國內資本市場的高溢價使得眾多中概股企業踏上私有化回歸A股之路。據統計，自2015年至2016年6月，準備私有化的中概股達到37家。近3年已有6家在海外上市的中國企業回到中国市場上市。2015年，自從中概股暴風影音從美國私有化退市回到了中國股市，創造了連續27個漲停的神話，中國的資本市場就掀起了一股中概股私有化回歸的熱潮。2015年，分眾傳媒成功借殼七喜控股回歸，被稱為是中概股回歸的大型樣本；2016年巨人網絡借殼世紀遊輪成為第二個回歸中国股市的中概股。
在現實決策中，這些中概股公司何時選擇私有化退市的時機是一個非常重要的問題，時機的選擇關係到公司能否順利實現重新上市，影響其後續的融資計劃和未來的發展前景。本文運用實質選擇權的思路解決這個問題，將公司擁有的私有化退市後重新上市的時機看做一種實質選擇權，公司一旦選擇私有化退市，就是執行了實質選擇權。本文以2014年7月完成私有化退市後於2016年4月借殼世紀遊輪迴歸中國股市的巨人網絡公司為例，通過實質選擇權的方法，對巨人網絡從美國市場私有化退市的時機選擇進行評估，給公司管理層提供有效的參考依據。

China concept stocks refer to the overseas listing and to the territory of China's assets or revenue as the main component of the stock in general. Since the early 90s of the 20th century, shares in the US stock market has been more than 20 years. However, in 2011, the first time in the stock market tide, in addition to some poor quality of small and medium enterprises passive delisting, part of the high free cash flow or high-quality enterprises choose to take the initiative to withdraw from the privatization. The value of China concept stocks are seriously underestimated in overseas market, and the high premium of the domestic capital market makes many of the enterprises return to Chinese stock market. According to incomplete statistics, from 2015 to June 2016, 37 companies had offered privatization request. In the last 3 years, 5 enterprises have left from the overseas stock market and returned to the Chinese stock market. In 2015, the storm video delisted from the US privatization got back to the Chinese stock market, creating a myth of 27 consecutive daily gains. In 2015, Focus Media was described as a large sample of the return of China Game. In 2016, Giant Network became the second Chinese stock market to return to China. In the real decision-making, the time the companies to choose to privatization delist is a very important issue, the timing of the choice related to the company can successfully re-listed, affecting its follow-up financing plan and future development prospects. This article uses the idea of real options to solve this problem. The company has the option to decide whether and when to privatization delist from American market. Once it decides to do it, it means that the option has been executed. In this paper, we use the Giants Network Company as an example, which completed the privatization delisting in 2014 and returned to Chinese stock market by reverse takeover the Century Cruises Company in 2016. We can assess the timing point of privatization delisting that the company chose through the method of real options，providing an alternative and effective reference standard for company management in the future.

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