Share your insights or perspective on the financial matter presented in the input.

buying a stock while the price is going down, and buy it at a lower price
In the US, it is perfectly legal to execute what you've described. However, since you seem to be bullish on the stock, why sell? How do you KNOW the price will continue downwards? Aside from the philosophical reasoning, there can be significant downside to selling shares when you're expecting to repurchase them in the near future, i.e. you will lose your cost basis date which determines whether or not your trade is short-term (less than 1 year) or long-term. This cost basis term will begin anew once you repurchase the shares. IF you are trying to tax harvest and match against some short-term gains, tax loss harvesting prior to long-term treatment may be suitable. Otherwise, reexamine your reasoning and reconsider the sale at all, since you are bullish. Remember: if you could pick where stock prices are headed in the short term with any degree of certainty you are literally one of a kind on this planet ;-).  In addition, do remember that in a tax deferred account (e.g. IRA) the term of your trade is typically meaningless but your philosophical reasoning for selling should still be examined.