"If I had invested $100 in Bitcoin in 2010, I would now have $3 billion."

No.
If you bought $100 worth of Bitcoin in 2010 and watched it increase:
$1,000 → $100,000 → $2 million
and did nothing
Then watched $2 million grow to $200 million
and still did nothing
Then watched $200,000 grow to $150 million
and still did nothing
Then watched $150 million decrease to $25 million
and still did nothing
Then watched $25 million skyrocket to $500 million
and still did nothing
Then watched $500 million decrease to $100 million
Then watched $100 million grow to $2 billion
and still did nothing
Then watched $2 billion decrease to $400 million
and still did nothing
Then watched $400 million skyrocket to $3 billion
and then, for some reason, finally decided to do something…
So yes, $100 in 2010 would be worth $3 billion today.