QUESTON IE THE 58P SOD IRCUUDSON AACMARY. Fig. 2.4 Mean Cumulative Abnormal Returns For Stocks Added To the S\&P 500, By Level Of Imperfect Arbitrage Risk. This figure, which we discussed in the lecture, plots the mean cumulative abmomal retums of two groups of stocks added to the SEP 500. The first group inchudes stocks with high arbitrage riak, while the other group includes stocks with low aroitrage risk. The horizontal axis is the trading day relative to the addition announcements. 1. (2 points) What is the main finding of this Figure? 2. (3 points) What is the explanation for the finding