How can one determine if those, mostly tech and pharma, companies with the largest percentage of retained foreign earnings (i.e. overseas cash)…

…. are repatriating their cash now that it is no longer prohibitive to do so under Trump's tax law?

Until recently it was very easy: companies would simply disclose the amount of cash held offshore vs domestically in the “Liquidity and Capital Resources” section of their public filings, as Apple did in its latest 10K:

As of July 1, 2017 and September 24, 2016, the Company's cash, cash equivalents and marketable securities held by foreign subsidiaries were $246.0 billion and $216.0 billion, respectively, and are generally based in U.S. dollar-denominated holdings

Alas, that is no longer the case because in its two latest 10-Q filings, Apple stopped revealing how much cash is held offshore. And not just Apple but, as Bloomberg discovered, so did all the other companies that collectively have hundreds of billions in cash parked overseas, including Netflix, Microsoft, Google and Oracle.

While there is certainly nothing “rule-breaking” about leaving offshore cash from one's disclosures – and according to Bloomberg, some tax experts say it makes perfect sense – the move could make it more difficult to gauge whether one of the federal tax changes enacted last year is stoking corporate investment in the U.S., as the Trump administration said it would.

To be sure, Trump did everything in his power to incentivize companies to repatriate offshore cash: according to the new tax law, there is a one-time rate of 15.5% on cash and 8% on non-cash or illiquid assets, with payments stretching as long as eight years. Previously, companies kept their cash offshore due to the prohibitive repatriation tax rate of 35%, which is why Apple, with its massive overseas cash hoard, would also end up issuing over $100 billion in debt domestically: to fund US-based dividends and stock buybacks.