I don't know what caused the sell off (just more volume selling than buying.)

Don't really need to know the "Why" but we know that gold and silver markets are more driven by paper assets and derivatives than physical gold and silver. 

I see this as shaking out the weak hands before a significant move to the upside. (This is just one person's opinion)

I also think the move in $USD won't last for more than few days to few weeks - similar to what we saw in March 2021 with some volatile market action. 

It's an opportunity to buy more gold and silver.  

[(Disclosure: Personally, I have call options on GLD (180C Nov, 2021), SLV (26C Sep 2021),  (26C Oct 2021, (30C June 2022),  (25C Jan 2023)]. I like the potential of silver more than gold as a technician.   

I don't recommend trading these options short terms (probably the worst instruments for short-term trading less than 1~2 months for the like 90% of the time. 

Here are weekly & daily chart of /GC (Gold Futures) then /SI (Silver Futures).

Please refer to the video within. 
 
Video 

https://www.youtube.com/watch?v=wITnMmivIQ0

Screenshots

Also if you're interested I talked about $DXY little bit in this post

https://exchange.realvision.com/question/raoul-thinks-copper-is-still-going-to-go-higher-yet-marin-katusa-says-there--60bd1e89cf132c6f1b3d3748