I recently picked up a used 27" 4k monitor for $50 - at that price, I had to buy it and wanted to see if it would integrate well with my 24" multi-monitor setup. My viewing distance is ~28". At 4k resolution w/o scaling, I can see the charts and make out the candlesticks, but forget about reading the numbers. At 125% scaling, I can read the numbers with a little effort. I could get by on this if I only had charts on here I wasn't looking at very often. Realistically, I need to use 150% scaling to comfortably use this monitor. But of course this gives up a lot of real estate. Given that a 27" 4k monitor at 150% scaling works for my eyes, how large a monitor would I likely need for 4k resolution at 100% scaling? 32"? 43"? And as the monitors get larger, would I have to increase viewing distance from my current ~28"? The 24" multi-monitor setup works for me, but intrigued by the notion that 1 x 4k monitor could replace 4 x 24" HD monitors without losing any screen real estate. Desk real estate is another concern - with 5 x 24" monitors on my desk already, the only option for that 27" 4k monitor was portrait orientation - which isn't bad, it's still shorter than 2 x 24" monitors stacked in landscape, so I don't have to crank my neck further. But seems 32" in portrait could be a neck-wrecker.