That $100 was most likely due to the original Dash listing on Coinbase and Coinbase Pro (also known as the Coinbase effect) and the
countless other recent integrations. Just check Dash News for news about Dash.
Link :
https://dashnews.org/Strange, because a couple of days ago I wanted to transfer my money from Yobit and choose Dash to save on fees and when I tried to send it to my Coinbase Pro account to trade further I couldn't because there was no deposit option for Dash. Additionally, I was looking at trading pairs and there is no Dash in USDT, ETH, Euro, USD or any other pairs.
When was Dash exactly added to Coinbase Pro?
https://blog.coinbase.com/dash-dash-is-launching-on-coinbase-pro-dec7e2da704On Monday September 16 at 10am PST, transfer DASH into your Coinbase Pro account ahead of trading. Support for DASH will be available in Coinbase’s supported jurisdictions, with the exception of New York State and the United Kingdom. Additional regions may be added at a later date.
Trading will begin on or after 9AM Pacific Standard Time on Tuesday, September 17, if liquidity conditions are met.
Any chance you are from the UK or New York State ?
If not, then its maybe best to check with Coinbase Pro directly.
By the way, Dash only has two pairs on Coinbase Pro :
DASH-BTC
DASH-USD