Where did I invest on Friday 12/14?

Markets were down from the beginning of the day. I wanted to buy more of  some stocks like TWILIO, OKTA or COUP. Instead I bough 10 stocks of IRIDIUM at 21, which later was down by another almost 4 %

Also by the end of the day Costco fell by a great margin, I bought it at 207.70 and final price for the day was 207.06. I guess, it should increase by a factor of 5 % within next 3 days of business. Also purchased 1 Coup at 64.46 and 2 TWILIO at 92. 

I started with 500 $ in September added another 450 in October. Current value is 960 and highest was 991 during first week of December. If I cross 1000 this week, I plan to sell all including Roku, which is showing  123 $ loss and square showing ~ $10.

Investing Strategy for Thursday 12-13

Let’s see what I already have, in Merrill Edge, I have Roku and Square. Sold Yesterday, Twilio, Okta and Coup.

I would like to buy MDB today, if it goes down by more than 3 % and also Twilio, Okta and Coup if they go down more than 5%. Regarding, Roku and Square, I plan to sell if any of them go beyond 5%, may buy more of Roku or Square, if they drop by more than 3%

Update: Although there was some fluctuation in the market, I chose not to buy or sell anything