Arconic(ARNC) tumbled to the bottom of theS&P 500today as the stock continues to slide following reports itssiding was used in the London high rise that caught fire. ILLUSTRATION:GETTY IMAGES Arconic dropped 9% to $21.84 today, while the S&P 500 fell 0.8% to 2,419.38. Arconic wasthe worst-performing stock in the S&P 500for a second consecutive day. Morgan Stanley's Rajeev LalwaniandBrendan Newman"remain on the sidelines" in Arconic: We remain on the sidelines given conflicting information regarding the legal implications. With limited information regarding the likely legal implications behind the recent incident and despite shares pricing in a notable hit ($1B+), we believe it is best to remain on the sidelines until we have more clarity on the potential outcomes (though we will continue to monitor the situation). Overall, we are still comfortable with being Equal-Weight shares despite them falling ~6% on Monday following the weekend's news and the company announcing the discontinuation of global sales of Reynobond PE for use in high-rise applications. And there is potential for this to be drawn-out and is just the beginning. Lastly, our fundamental work has highlighted significant execution ahead and the recent developments could stall (or alter) the hiring of a new CEO as the board may have to shift its focus. Arconic's market capitalization fell to $9.6 billion today from $10.6 billion yesterday. It reported a net loss of $1.1 on sales of $12.4 billion in 2016. from Barron's