本研究以國內外分析師對台灣50指數和中型100指數成分股的標的公司研究報告共10,410筆樣本，研究期間自2019年1月至2021年1月，並以2020年1月14日為基準，分為COVID-19爆發前後兩段研究子期間，分別探討國內外分析師在COVID-19衝擊下，是否影響投資評等和目標價預測達成率及準確度，並將預測期間分為一個月和三個月，分析兩段研究子期間的目標價達成時間長短是否改變，最後針對外資研究報告樣本進行迴歸分析探討影響目標價準確度的因素。
本研究結果可列為以下四點：一、COVID-19影響下國內外分析師發布研究報告目標價的達成率降低，且不論COVID-19前後，外資分析師預測目標價達成率較本國券商高；二、COVID-19影響下目標價達成時間縮短往一個月集中；三、COVID-19影響下國內外券商對於正向評等預測過度樂觀，對於負向評等預測過度保守，其中，外資券商正向評等的目標價準確度較高；本國券商負向評等的目標價準確度較高；四、不論在COVID-19前後，外資持股比率愈高的股票，目標價預測誤差愈小。

This research uses 10,410 analyst reports on Taiwan Top 50 ETF and Taiwan Mid-Cap 100 ETF from domestic and foreign analysts. The data period is from January 2019 to January 2021, and is divided into sub-periods based on January 14, 2020, during COVID-19 outbreak. The research will discuss whether COVID-19 will affect the achievement rate and accuracy of investment rating and target price predicted by domestic and foreign analysts. Moreover, to test the length of time to reach the target price in the sub-periods, the research use two forecasting periods: one month and three months. Last, running the regression analysis on foreign analyst reports to explore the factors that affect the accuracy of the target price.
The results of this research can be listed as follows: First, under the influence of COVID-19, the achievement rate of target prices issued by domestic and foreign analysts has decreased, and regardless of COVID-19, the achievement rate of target price predicted by foreign analysts is higher than that by domestic analysts; Second, under the influence of COVID-19, the length of time to reach the target price has been shortened and concentrated in one month; Third, under the influence of COVID-19, domestic and foreign analysts are overly optimistic about the target prices of positive recommendations, and they are also overly conservative about the target prices of negative recommendations. Besides, foreign institution analysts forecast the target prices of positive recommendations more accurate; domestic analysts forecast the target prices of the negative recommendations more accurate; Fourth, The higher the foreign shareholdings ratio, the smaller the target price error.

池祥萱、蕭君怡（2005），券商投資評等報告的資訊內涵-本國券商與外資券商的比較，《金融風險管理季刊》，第1 卷第3 期，27-45。
李懷玉（2007），投資評等績效評估，國立中山大學財務管理學研究所碩士論文，高雄市。
周漢文（2011），券商研究報告之價值-以台灣為例，國立臺灣大學財務金融學研究所碩士論文，臺北市。
林志瀚（2007），券商評等對台灣股市的影響，國立中興大學財務金融研究所碩士論文，臺中市。
林美珍、張文菖（2016），台股目標價預測準確度之探討，證券市場發展季刊，第28卷第2期，1-36。
林靖庭、張清發、陳威光(2017)券商推薦股票評等報告之績效分析，風險管理學報，第19卷第2期，116-140。
張裕任、吳琮璠、王泰昌（2012）影響外資持股偏好因素之探討：安全性及資訊不對稱，證券市場發展季刊，24卷1期，1-44。
陸逸威（2013），外資券商分析師投資評等與目標價修正之宣告效果探討，國立臺北大學經濟學研究所碩士論文，新北市。
黃薇甄（2008），不同景氣循環階段下之券商推薦資訊內涵，國立成功大學國際企業研究所碩士論文，臺南市。
楊儀專（2016），市場模糊之際，證券商推薦評等是否有從眾行為，國立臺北大學企業管理學研究所碩士論文，新北市。
謝文良、李進生、王芊儒（2013），台股外資分析師報告預測目標價之正確性與影響因素分析，《臺大管理論叢》，第24 卷第1 期，43-70
Ahmed, K. and J. K. Courtis (1999), “Associations between Corporate Characteristic and Disclosure Levels in Annual Reports: A Meta-Analysis,” British Accounting Review, Vol. 31, 35-61.
Anderson, Jonas, and Martinez(2020), “Measuring the Added Value of Stock Recommendations,” Journal of Financial and Quantitative Analysis, Vol. 55, No. 6, 1915-1945.
Bailey, W. and J. Jagtiani (1994), “Foreign Ownership Restrictions and Stock Price in the Tai Capital Market,” Journal of Financial Economics, Vol. 36, 57-87.
Barber, B., R. Lehavy, M. McNichols, and B. Trueman (2001), “Can Investors Profit from the Prophets? Security Analyst Recommendations and Stock Returns,” Journal of Finance, 56, 531-563.
Beneish, M.D. (1991), “Stock Prices and the Dissemination of Analysts’ Recommendation,” The Journal of Business, 64, 393-416
Bonini, S., Zanetti, L., Bianchini, R., & Salvi, A. 2010. Target price accuracy in equity research. Journal of Business Finance & Accounting, 37 (9-10), 1177-1217.
Bradshaw, M. T. (2002), “The use of target prices to justify sell-side analysts’ stock recommendations.” Accounting Horizons, 16 (1), 27-41.
Bradshaw, M. T., L. D. Brown and K. Huang (2013), “Do Sell-side Analysts Exhibit Differential Target Price Forecasting Ability,” Review of Accounting Studies, Vol. 18, No.4, 930-955.
Brav, A. and R. Lehavy (2003), “An Empirical Analysis of Analysts' Target Prices: Short‐term Informativeness and Long‐term Dynamics,” Journal of Finance, Vol. 58, No.5, 1933-1968.
Chang, Y.H. and C.C. Chan (2008), “Financial Analysts’ Stock Recommendation Revisions and Stock Price Changes,” Applied Financial Economics, 18, 309-325
Falkenstein, E. G. (1996), “Preferences for Stock Characteristics as Revealed by Mutual Fund Portfolio Holdings,” The Journal of Finance, Vol. 51, 111-135.
Lang, M. H. and R. J. Lundholm (1996), “Corporate Disclosure Policy and Analyst Behavior,” The Accounting Review, Vol. 71, 467-492.
Moskowitz, Tobias J., and Mark Grinblatt(1999), “Do Industries Explain Momentum?” Journal of Finance, 54, 1249-1290.
Michaely, R., & Womack, K. L. 1999. Conflict of interest and the credibility of underwriter analyst recommendations. The Review of Financial Studies, 12 (4): 653-686
Narasimhan Jegadeesh, Joonghyuk Kim, Susan D. Krische and Charles M. C. Lee (2004), “Analyzing the analysts: When do recommendations add value?” Journal of Finance, Vol. 59, No. 3, 1083-2004
Petersen, M. A. (2009), “Estimating Standard Errors in Finance Panel Data Sets: Comparing Approaches,” Review of Financial Studies, Vol. 22, No.1, 435-480.
Thomas Lys and Sungkyu Sohn(1990), “The Association between Revisions of Financial Analysts’ Earnings Forecasts and Security-Price Changes,” Journal of Accounting and Economics, 13, 341-363.
Womack, K, (1996), “Do Brokerage Analysts’ Recommendations Have Investment Value?” Journal of Finance, 51, 137-167.