Bitcoin has plunged almost 20% since Standard Chartered predicted the crypto could surge to $120,000

• Bitcoin has plunged almost 20% since the second week of July, when Standard Chartered predicted it could surge to $120,000. 
• The cryptocurrency had a weak August, losing more than 11% and falling for a second straight month. 
• Bitcoin's decline comes amid a broader sell-off in financial markets. 

The world's biggest cryptocurrency has plunged nearly 20% since Standard Chartered predicted it could reach $120,000 next year.