Libraries Used

For this project we’ll use three libraries:

• Twilio: to send message
• Quantmod: to get the stock prices
• dplyr: for data processing prcedures

Setting up Environment VAriables

To use Twilio we need to set up two system environment variables in R: TWILIO_SID and TWILIO_TOKEN.

We’ll use Sys.setenv() function to set these environment variables as follows:

Sys.setenv(TWILIO_SID = “TWILIO_SID_NUMBER”)
Sys.setenv(TWILIO_TOKEN = “TWILIO_TOKEN_NUMBER”)

# LIBRARIES ----
library(quantmod)
library(twilio)
library(dplyr)

Sys.setenv(TWILIO_SID = 'ACf43caa6608884e01b935971dffce9d54')
Sys.setenv(TWILIO_TOKEN = '2c68a2e9f06ac668e105f4c806374929')

Wrapper Function for Sending SMS

The following wrapper function send_msg() will allow us to update the body of the message dynamically to show the stock name, updated price and other information.

# SEND MESSAGE ----
send_msg = function(body){
  tw_send_message(
  to = Sys.getenv("YOUR_VARIFIED_CELL_NO"),
  from = Sys.getenv("YOUR_TWILIO_CELL_NO"),
  body = body
)
}

Wrapper Function for Stock Price Check

This wrapper function stock_price_check() will allow us to automatically run getQuote() function to get stock price detail about our desired stocks. stock_price_check() is basically a while loop which will keep executing on certain intervals until the loop is stopped manually.

The tasks that will be completed inside stock_price_check() look like this:

stock_price_check = function(tickers, price, quantity, threshold){
while(logic){
1. Fetch Stock Price
2. Calculate Profit 3. Print the Calculations in the R Console
4. Check if the Profit Meets the Set Threshold
4.1 If meets threshold: send a SMS
4.2 If doesn’t meet threshold: do nothing
5. Wait for a Certain Interval
6. Repeat Steps 1 to 5 } }

# Fetch stock price and send SMS
# @param tickers A String vector of stock tickers 
# @param price A numeric vector of stock prices. In the same order of tickers
# @param quantity A numeric vector of stock quantity purchased. In the same order of tickers
# @param threshold A numeric input that shows the desired profit margin. Defaults to 4%


stock_price_check = function(tickers, price, quantity, threshold = 4){
  
  # setting up a counter. 
  i = 0 

  
  while(i < 2){ 
    
    # Step 1. Fetching stock price
    latest_price = quantmod::getQuote(tickers)
    
    # Step 2. Calculating profit
    latest_price[['Buy']] = c(price)
    latest_price[["Q"]] = c(quantity)
    latest_price[["Profit/Loss"]] = c(latest_price[["Last"]] - latest_price[["Buy"]])
    latest_price[["Total_PL"]] = c(latest_price[["Profit/Loss"]] * latest_price[["Q"]])
    latest_price[["Total_PL%"]] = c(round(latest_price[["Total_PL"]] / (latest_price[["Buy"]] * latest_price[["Q"]]) * 100, 2))
    
    # Stp 3. Printing out calculations in R console
    print(latest_price[c('Trade Time', 'Last', 'Buy', 'Total_PL', 'Total_PL%')])
    cat("\n")
    
    # Step 4. Checking if the profit meets desired profit threshold
    df = as.data.frame(latest_price) %>%
      filter(`Total_PL%` > threshold) 
    
    if(nrow(df) > 0){
      # Step 4.1 Sending SMS if profit meets threshold
      msg = paste0(threshold, "% profit alert!\n",  
                   paste0(rownames(df), 
                          ": Profit %: ", df[,"Total_PL%"], 
                          "| Total Profit: ", round(df[, "Total_PL"]),
                          collapse = ' ; \n'))
      send_msg(body = msg)
      message(msg)
    }
  
  # Step 5. Waiting for certain interval (60 seconds)
  Sys.sleep(60)

  # Step Drop: Incrementing counter
  i = i + 1 # comment out this line when you run. I had to put an increment to make sure the while loop stops after 4 execusions
  }
}

Now let’s assume that we own a mini portfolio of two stocks Best Buy (BBY – 14 stocks purchased at $114.09) and HP Enterprise (HPE – 645 stocks purchased at $9.30). And we are interested to set up a reminder that will notify us once any of the stocks in the portfolio reaches to 4% profit margin.

Note that I have set the function to run only twice. Make sure the comment out the counter increment inside the function.

stock_price_check(tickers = c("BBY", "HPE"), price = c(114.09, 9.30), quantity = c(14, 645))
##              Trade Time   Last    Buy Total_PL Total_PL%
## BBY 2020-08-28 16:00:01 111.23 114.09   -40.04     -2.51
## HPE 2020-08-28 16:03:43   9.83   9.30   341.85      5.70
## 4% profit alert!
## HPE: Profit %: 5.7| Total Profit: 342
##              Trade Time   Last    Buy Total_PL Total_PL%
## BBY 2020-08-28 16:00:01 111.23 114.09   -40.04     -2.51
## HPE 2020-08-28 16:03:43   9.83   9.30   341.85      5.70
## 4% profit alert!
## HPE: Profit %: 5.7| Total Profit: 342