If you watch funding announcements as we do, you may have noticed something this year. There are a lot of mega-rounds coming together, and Tiger Global is involved in a notable number of them, often as the round’s co-lead. Just this week alone, half a dozen companies have announced rounds that the New York-based investing giant has led, co-led or written follow-on checks into, including HighRadius, a company whose $300 million Series C round it co-led with D1 Capital; Cityblock Health, whose $192 million in extended Series C funding Tiger…