This isn't directly related to bitcoin, but I just thought people should know more about this. There have been proposals for bitcoin ETFs to the SEC, and got rejected at least twice.

Question: Explain what is an ETF and how it works?

---

Apologies for not being around for this thread. Have lot a personal issues going around.

What is Exchange Traded Fund:
Exchange Traded Fund most like stock exchange. Those fund use to be traded on stock exchange that's called EFT. From ETF you can track all tradable assets and you can trade from there. That means you can track price buy and sale to other investor through stock exchange.
ETF become most popular  due their low cost facility. There is many broker for buy sale assets. I just share my basic idea about ETF. If you want to know more details please visit Wikipedia.

How will be benefited crypto or Bitcoin holder's from ETF:
If U.S. Securities and  Exchange Commission (SEC) approve EFT application than many big investor will start invest on Bitcoin/crypto-currency. Because Bitcoin or other crypto-currency will consider like an asset. So crypto currency will be open diverse set of investors. There will be no restrictions for crypto currency. For that reason crypto currency price will increase rapidly. Those will buy Bitcoin or other crypto-currency they can track real time price from ETF and can sale to other investors.

However, what I understand that if SEC approve EFT than crypto revolutions will be unbelievable.  Most of crypto currency will be up trend. We can see currently just discussing about EFT on SEC board & price of Bitcoin on bulls run. We expect SEC will consider EFT application on middle of August.

In  cryptography,  the  avalanche  effect  refers  to  a
desirable  property  of  cryptographic  algorithms,
typically  block  ciphers  and  cryptographic  hash
functions. The avalanche effect is evident if, when an
input is changed slightly (for example, flipping a single
bit)  the  output  changes  significantly  (e.g.,  half  the
output  bits  flip).  In  the  case  of  high-quality  block
ciphers, such a small change  in either  the key  or the
plaintext  should  cause  a  drastic  change  in  the
ciphertext.
If a  block cipher or  cryptographic hash function does
not exhibit the avalanche effect to a significant degree,
then it has poor randomization, and thus a cryptanalyst
can make predictions about the input, being given only
the  output.  This  may  be  sufficient  to  partially  or
completely  break  the  algorithm. Thus,  the  avalanche
effect is a desirable condition from the point of view of
the designer of the cryptographic algorithm or device.

(PDF) Study of Avalanche Effect in AES. Available from: https://www.researchgate.net/publication/304141002_Study_of_Avalanche_Effect_in_AES [accessed Aug 23 2018].