Here's a couple things for you to consider, because apart from you asking about specific positions, I think this is a great question even though specific advise is off topic.
Volatility just means the value of the asset isn't stable from day to day, to some extent that means your outcome is not predictable. The whole stock market is volatile. Sure, there are volatility measures to track the past volatility of a given security against another security or group of securities, but that doesn't really say much about will happen tomorrow than a price chart.
Risk is really, will this asset even have any value at all tomorrow? What is the likelihood my $1,000 becomes $0?
So, now there's just math.
Say you put $500 in to an account and add $50 each month for 4 years, your contributions = $2,850. Add in an attainable 1.6% interest rate and you end up with $2,960.
Now lets add in some volatility and risk, looking at the S&P500 the average 4 year return is 12.4%, pretty good! The maximum 4 year return is 31.9%, really good!! The minimum though is -21.5%. So respective 4 year account balances are approximately $3,865, $6,457, and $1,779. This is the S&P500, the 500 largest large cap companies. Are you looking for more risk than this? More volatility? The "safest" way to invest in the stock market is many orders of magnitude more volatile and risky than a savings account.
Now you just get in to fees and your expected contributions and really, the only logical conclusion is an extremely low expense ratio, no-commission, no-fee mutual fund. If you have to pay even a low commission of $5 on your trades you'll give up $240 of your $2,850 just to buy these assets.
Even though it's probably off topic, and assuming that you have some kind of core assets in an emergency fund, you should find a solid brokerage (Vanguard, Schwab, Fidelity) open your taxable brokerage and buy shares of a fund like SWTSX. Buy the mutual fund because you can buy fractional shares, so your whole $50 can go in to the market every month and you'll only pay 0.03% to expenses every year.