The fictional comic superhero Superman has a weakness regarding Kryptonite; Bitcoin is a cryptocurrency. “Bitcoin is cryptonite superman!” was posted on Twitter on August 18, 2014. “Is ‘cryptonite’ like cryptocurrency, is superman’s fatal weakness bitcoin” was posted on Twitter on September 5, 2014. “Why doesn’t Superman invest in Bitcoin? He can’t stand Cryptonite” was posted on Twitter on December 1, 2017.
   
A riddle was posted on Reddit—Bitcoin on December 23, 2017:
   
Q: Why does superman only daytrade bitcoin?
A: Because he can’t go near .(JavaScript must be enabled to view this email address).
 
A similar riddle was posted on Reddit—Bitcoin on January 21, 2018:
 
Q: Why does Superman hate trading Bitcoin after 7pm?
A: Because it’s Crypto-night.
   
   
Wikipedia: Superman
Superman is a fictional superhero appearing in American comic books published by DC Comics. The character was created by writer Jerry Siegel and artist Joe Shuster, high school students living in Cleveland, Ohio, in 1933. They sold Superman to Detective Comics, the future DC Comics, in 1938. Superman debuted in Action Comics #1 (cover-dated June 1938) and subsequently appeared in various radio serials, newspaper strips, television programs, films, and video games. With this success, Superman helped to create the superhero archetype and establish its primacy within the American comic book. The character is also referred to by such epithets as the Big Blue Boy Scout, the Man of Steel, the Man of Tomorrow, and the Last Son of Krypton.
     
Wikipedia: Kryptonite
Kryptonite is a fictional substance which is the most well-known weakness of the DC Comics superhero Superman. Kryptonite is the ore form of a radioactive element (prior to Crisis on Infinite Earths) or compound (post-Crisis) from Superman’s home planet of Krypton. The popularity of Superman and his vulnerability to Kryptonite has led to the generic usage of the term in popular culture as a reference to an individual’s weakness, similar to “Achilles’ heel”.
 
Wikipedia: Bitcoin
Bitcoin is a cryptocurrency and worldwide payment system. It is the first decentralized digital currency, as the system works without a central bank or single administrator. The network is peer-to-peer and transactions take place between users directly, without an intermediary. These transactions are verified by network nodes through the use of cryptography and recorded in a public distributed ledger called a blockchain. Bitcoin was invented by an unknown person or group of people under the name Satoshi Nakamoto and released as open-source software in 2009.
       
Twitter   
Nico‏
@nicoamorescom
Replying to @CRYPT0N1TE
@CRYPT0N1TE @devnullius @richieredeyes Bitcoin is cryptonite superman!
7:10 PM - 18 Aug 2014
     
Twitter
CC Kirby‏
@_cckirby
Replying to @MiraVylash
@CureVylash is “cryptonite” like cryptocurrency, is superman’s fatal weakness bitcoin
3:05 PM - 5 Sep 2014
 
Twitter
GC Guy‏
@foam_gc
Replying to @crypto_wise
Why doesn’t Superman invest in Bitcoin?
He can’t stand Cryptonite.
3:59 PM - 1 Dec 2017
 
Reddit—Jokes
Superman seems to hate Bitcoin.
submitted December 13, 2017 by rape_is_intolerable
I guess it’s his cryptonite.
 
Reddit—Bitcoin
Dad Joke - Why does superman only daytrade bitcoin (self.Bitcoin)
submitted December 23, 2017 by toddmo
Because he can’t go near crypto@night
 
Reddit—Jokes
Why does Superman only daytrade bitcoin?
submitted December 23, 2017 by Eastonator12
Because he can’t go near crypto@night
 
Reddit—Bitcoin
Why does Superman hate trading Bitcoin after 7pm? (self.Bitcoin)
submitted January 21, 2018 by dannydomenic
Because it’s Crypto-night
 
Reddit—Dad Jokes
Why does Superman hate trading Bitcoin after 7pm? (self.dadjokes)
submitted January 21, 2018 by jonathanbeaumont0
Why does Superman hate trading Bitcoin after 7pm? Because it’s crypto-night
 
Twitter
BitcoinOutsider‏
@bitcoinoutsider
Why doesn’t Superman own Bitcoin Cash? Because it’s Crypto-nite.
10:16 PM - 21 Jan 2018