Here's ETF flows for the first six weeks of the year historically. This year is off to the best start almost by double. One reason is growing depth of cash vacuum cleaners. VOO, SPYM hoovering as always but there's already over 500 ETFs with >$100m in flows, many you've never heard of. Model portfolios, BYOA and legacy active are giving ETFs a big extra wave of money.(Eric Balchunas)