CNBC
Jeff Cox
Sept. 10, 2018
Companies took major advantage of last year's tax cuts to bring home profits they had stored overseas.
In the first quarter alone, multinational enterprises brought home about $300 billion of the $1 trillion held abroad, according to a recent Federal Reserve study. A good chunk of that repatriated money went to share repurchases — for the top 15 cash holders, some $55 billion was used on buybacks, more than double the $23 billion in the fourth quarter of 2017.

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https://www.cnbc.com/2018/09/10/chart-shows-surge-in-corporate-cash-brought-home-since-tax-cuts.htmlI think the stock buybacks are a partial cause of the stock market run-up.