It’s a kind of de-risking—not in the sense that the particular blockchain, or blockchains in general, are now any less vulnerable to the attack (Sybil attacks generally are like the Halting Problem of open consensus systems—no real way around them) but rather that these attacks, for some investors, go from scary “unknown unknowns” to “known unknowns” that can be quantified in their impact, and thus ROI models can be clarified, making cryptocurrency’s value as an asset class more legible. Legible assets always have a place in a hybrid-strategy portfolio; while illegible assets (like illiquid real estate from the housing crash) almost never do.

> basically the reserve currency of the crypto world (roughly all exchanges will have it)

I would say that that’s more like either Monero or USDC right now: these are the cryptocurrencies people ask for when they just want cash but want to let you pay them in crypto, because you can cash out of crypto entirely in a non-value-losing way pretty well from either (with Monero, because it has low TX fees and fast processing times, so you can get rid of it in seconds; with USDC, because it’s stable-ish for now, so you don’t need to worry on a scale of minutes whether it’ll keep its value.)

Which is similar to what “reserve currency” means in practice for most people (other than banks): it’s the currency they’d prefer to be paid in, and the currency you’ll see them trading in their own currency for in the event that their own currency experiences high volatility.

This might be because the "halvening" is this year.

Also all stocks are down due to the corona virus. which is allegedly a reason bitcoin is high.

This is also not the first time this coin has been targeted.

Oops: I see what you mean though. Because there's so many BTC miners, they can easily swap over to BTG to overwhelm the much smaller network.