It's "upward" to the "black hole" represented by your own huge holdings. As someone said, if you're rich, you might as well give a lot to the poor because it'll come right back to you anyway. "Trickle down" is insignificant when it's pouring up.
Long before1% of the population accumulates 99% of the wealth - a situation that is entirely possible in our skimming and charity type of of capitalism - long before that the level of concentration starves the markets away from the propductivity you are targeting your investments to.
In other words, the biggest problem in the capitalist system is you, as long as you observe no guideline by which to reinvest in your own investment-bearing consumer markets and indeed, have no guideline in the first place. This is a corollary of Chesterton's pan-Utopian trap. Your concentration of wealth gets so extreme every 60-70 years that a Depression is triggered and the only way it is resolved is by war. War cuts down on the under-employed by killing and maiming them, raises wages by market forces and that basically forces you to reinvest in your own investment-bearing consumer markets at a much higher and more continous level, beside which your discretionary charity is a drop in the bucket (and charity bypasses and skews the market anyway).
The least arbitrary, most market-determined alternative to all this is a system of automatic reinvestment thresholds (ARTs). Below the ARTs, discretionary earnings may be derived. Above the ARTs, all earnings must be reinvested in training or hiring.
The thresholds themselves are not arbitrary or excessive. Initially, they're not even applied directly to income. That would create dependency and damage incentive. Initially, they're applied to employment per person per week. They're placed at some point on the workweek, either at the standard 40-hour level or at the longer level of your own average workweek. If the latter, it's gradually lowered to 40 at a rate determined by referendum of the consumer market targeted for rescuscitation. Thereafter it fluctuates, at that same rate, against underemployment. This gets rid of the arbitrariness of the 40-hour level itself and ensures that, despite variability at all levels except the top, the fact that the top level is tied to offset underemployment guarantees that consumer markets, are maximized - and with them, social harmony and stability.