Not real HDR. It'll accept an HDR10 signal, but it will not display it how it's meant to be seen because of: 8-bit panel, nowhere near the necessary peak/sustained brightness, no local dimming, no wide color gamut.
There are really VERY few options for true HDR sets, by which I mean sets that have a 10-bit panel, good local dimming, good black levels, can attain 1000nits, and wide color gamut). Further, I believe the UH5500 is one of the RGBW 4faKe LG panels. Options are pretty much: Samsung KS8000 (7000 in EU), Vizio P-Series, Sony X930D, LG B6/E6/G6 OLED. The OLEDs are prohibitively expensive, but you might find the smaller P-Series and KS8000 for cheap over the holidays. I would not personally recommend the Sony.