That SEC article was warning about people who promote investments as being a gauranteed high return and risk free. Well bitcoin bulls go even one step further than this, to tell you that holding cash itself is risky.
Cash is not risky. You are
guaranteed to lose, and the guarantee is backed by the full coercive force of the largest government the world has ever seen.
Not even gold is a guaranteed winner every year, because it is only backed by free market.
Let me reprhrase this then... Bitcoin bulls go one step further to tell you not only is Bitcoin risk-free but that if you aren't holding bitcoins, you are taking a risk because holding fiat is risky and bitcoin is clearly the way out of that risk. So bitcoin is not only risk free, but acts as an inverse risk. It is the infallible investment made in heaven and you you need to buy buy buy or die. They are not only going to quell your fears about holding bitcoin but make you fear NOT holding bitcoin. Because bitcoin is the solution for the apocalypse and when the system fails, bitcoiners will become filthy rich. It is the DESTINY. Bitcoin is like a rapture and you need to be on board or be left to perish.
Not risk free. There is a risk, but also a reward. You can assert the probability to each of a few possible outcomes, and compute an aggregate expectation.
You can also do that with fiat, there is a small risk of deflation, which will give you a positive reward (if you can catch it flying by), there is a risk of 2% loss if you believe the current statistics, 5% if you don't. Then there is a real risk of stagflation, where the inflation rate can come up to 20 % easily.
So the expectation, modified by risk, is say 5 percent loss in case of fiat, and conservatively a 100 percent gain in bitcoin.