This is my entry to 
Here is my joke and I hope you will like it. :-)
source
On April 21, 2017, a woman called up a bakeshop to order a cake for her wedding on December 21.
Woman: I'll pay you 200 SBD for the cake. I just want you to make the wedding cake simple yet elegant. SBD is stable at $1 so there shouldn't be any huge changes in seven months' time.
Baker: Okay, I'll accept 200 SBD. I can make a decent cake from that. May I know the number of people that are invited?
Woman: Just 40 Steemit friends. I'll send you the final guest list maybe a week from now.
Baker: All good. We'll take care of business.
Come the Wedding Day, the woman was surprised to see a really really huge wedding cake sitting outside the church. It was the biggest that she has ever seen in her life; a two storey chocolate cake as wide as a track field. The woman hurriedly went to the baker to ask about the cake.
Woman: Hi. I am aware that SBD went from $1 to $13 in seven months, so did the value of 200 SBD that I paid you in April. But I think that the cake that you made is too big for 40 guests.
Baker: Ah, yeah. My assistant doubled-checked your guest list and looked at their Steemit accounts too.
Woman: And what's with that? You can confirm that I only have 40 guests and not 40 thousand, right?
Baker: Of course. But my assistant told me that we are going to feed 40 whales.