There are likely to be losers from corporate income tax reform.  They’re likely to be of two types:

–companies that currently have sweetheart tax deals, which, as things stand now (meaning:  subject to the success of intensive lobbying), will go away as part of reform.  A related group is multinationals who’ve twisted their corporate structures into pretzels to locate taxable income outside the US

–companies making losses currently and/or that have unused tax-loss carryforwards.  The value of those unused losses will likely be reduced by a lot.  This is a somewhat more complicated issue than it seems.  In their reports to public shareholders, money-losing firms can use anticipated future tax benefits to reduce the size of current losses.  The ins-and-outs of this are only important in isolated cases, so I’ll just say that for such firms book value is likely overstated

Another potential consequence of tax reform is that investors may begin to take a harder look at tax-related items on the income and cash flow statements.  Could markets will begin to apply a discount to the stocks of firms that use gimmicks to depress their tax rate?  Thinking some what more broadly, it may mean the markets will take a dimmer view of other sorts of financial engineering (share buybacks are what I personally hope for).  It might also be that companies themselves will reemphasize operation experience rather than financial sleight of hand when choosing their CEOs.