本研究根據Philip, Shi and Yu（2015）所提出的檢測泡沫模型（PSY）並利用Phillips, Wu and Shi（2018）所提供的psymonitor R package搭配技術指標針對美國10家科技股公司進行實證研究。資料樣本為美國10家科技股公司之收盤價與每股銷售額之比率（price to sales ratio, P/S ratio），進行PSY泡沫檢定，若檢測出泡沫，則進行投資；或是加上技術分析後再決定是否進行投資，比較哪一種投資報酬率較高。實證結果顯示，使用PSY模型可以檢測出股價泡沫出現與結束時間，亦即佐證價格泡沫（price bubble）之存在。雖然，有時會出現假訊號，亦即不存在的泡沫，但若不考慮交易手續費的情況下，投資總報酬率仍為最高（674.75%），平均單次報酬率為6.31%。若加入技術指標，平均單次報酬率，明顯提升至21.92%，而交易次數，也有顯著的下降。

This research is based on the model suggested by Phillips, Shi and Yu (2015) for detection of bubble (PSY), also using the R package psymonitor provided by Phillips, Wu and Shi (2018) with technical indicators to conduct empirical research on 10 U.S technology stocks. The sample data is from the price to sales ratio (P/S ratio) of 10 U.S technology stocks. If the PSY detection detected bubble, then investment would be conducted, or add technical analysis, then decide whether to invest, comparing which one has a higher return. Empirical results indicated that by using PSY model, the appearance and the end of the stock price bubble can be detected, which can prove the existence of price bubble. Although false signals sometimes appear, which means bubble doesn’t exist, since the transaction fee is not considered, the total rate of return still remains the highest (674.75%), with a 6.31% average single return rate. In other words, if the technical analysis is added, the return rate of average per time will rise to 21.92% and the number of transaction drops significantly.

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