# Load packages
library(tidyquant)
library(tidyverse)

# Import stock prices
stock_prices <- tq_get(c("WMT", "TGT", "AMZN"), get  = "stock.prices", from = "2020-01-31")

# Calculate daily returns
stock_returns <-
  stock_prices  %>%
    group_by(symbol) %>%
    tq_mutate(select = adjusted, mutate_fun = periodReturn, period = "daily") 
stock_returns
## # A tibble: 66 x 9
## # Groups:   symbol [3]
##    symbol date        open  high   low close  volume adjusted daily.returns
##    <chr>  <date>     <dbl> <dbl> <dbl> <dbl>   <dbl>    <dbl>         <dbl>
##  1 WMT    2020-01-31  116.  116.  114.  114. 7775800     114.       0      
##  2 WMT    2020-02-03  115.  115.  114.  114. 4351900     114.      -0.00192
##  3 WMT    2020-02-04  115.  116.  115.  115. 5232200     115.       0.00875
##  4 WMT    2020-02-05  116.  117.  115.  117. 5682900     117.       0.0134 
##  5 WMT    2020-02-06  117.  117.  116.  116. 5352900     116.      -0.00428
##  6 WMT    2020-02-07  116.  117.  116.  116. 3689600     116.       0.00120
##  7 WMT    2020-02-10  116.  117.  115.  115. 6144900     115.      -0.0103 
##  8 WMT    2020-02-11  115.  116.  114.  115. 5796800     115.       0.00130
##  9 WMT    2020-02-12  116.  116.  115.  116. 4735600     116.       0.00390
## 10 WMT    2020-02-13  116.  118.  116.  117. 5333200     117.       0.0137 
## # … with 56 more rows

Q1 filter Select stock returns of January 31, 2020.

Hint: See the code in 1.2.2 Selecting observations.

Stock_Jan <- filter(stock_returns, date == "2020-01-31")
Stock_Jan
## # A tibble: 3 x 9
## # Groups:   symbol [3]
##   symbol date        open  high   low close   volume adjusted daily.returns
##   <chr>  <date>     <dbl> <dbl> <dbl> <dbl>    <dbl>    <dbl>         <dbl>
## 1 WMT    2020-01-31  116.  116.  114.  114.  7775800     114.             0
## 2 TGT    2020-01-31  113.  114.  110.  111.  6961900     110.             0
## 3 AMZN   2020-01-31 2051. 2056. 2002. 2009. 15567300    2009.             0

Q2 Which of the three stocks performed best on January 31, 2020?

Hint: Answer the question by comparing daily returns of each stock on January 31, 2020. Amazon performed the best on January 31, 2020

Q3 Plot the distribution of daily returns by stock using boxplots.

Hint: See the code in 4.3.3 Box plots. Add an appropriate title and labels for both axes.

ggplot(stock_returns,
       aes(x = symbol,
           y = daily.returns)) +
  geom_boxplot() +
  labs(title = "Distribution of Daily Returns", x = "Symbol", y = "Daily Returns")

Q4 Based on the boxplot above, which of the three stocks performed best this year?

Hint: Answer the question by comparing median and outliers of each stock. Amazon performed the best of the three

Q5 Calculate mean daily returns for each stock.

Hint: See the code in 4.3.1 Bar chart (on summary statistics).

avgreturns <- stock_returns %>%
  group_by(symbol) %>%
  summarize(mean_returns = mean(daily.returns))
avgreturns
## # A tibble: 3 x 2
##   symbol mean_returns
##   <chr>         <dbl>
## 1 AMZN      -0.00211 
## 2 TGT       -0.00158 
## 3 WMT       -0.000415

Q6 Plot mean daily returns using bar charts.

Hint: See the code in 4.3.1 Bar chart (on summary statistics). Add an appropriate title and labels for both axes.

ggplot(avgreturns,
       aes(x = symbol, 
           y = mean_returns)) +
  geom_bar(stat = "identity") +
  labs(title = "Mean Daily Returns", x = "Symbol", y = "Mean Returns")

Q7 Create the line plot of stock prices for all three stocks in one graph.

Hint: Google search something like “ggplot2 multiple lines”.

ggplot(stock_prices, aes(x = date, y = adjusted, group = symbol)) + 
  geom_line(aes(color = symbol)) + 
  scale_color_manual(values = c("goldenrod", "darkred", "steelblue")) +
  labs(y = "Adjusted Stock Price", x = "Date", title = "Daily Stock Prices")

Q7.a filter Create the same line plot as in Q7, but without Amazon.

Note: Insert a new code chunk below, copy and paste the code in Q7, and revise it using the dplyr::filter function. This is an extra credit question worth 10 points. However, the total number of points you could earn for this quiz is capped at 100 points. In other words, the extra credit can only offset any one question you missed in the first seven questions.

stock_prices2 <- tq_get(c("WMT", "TGT"), get  = "stock.prices", from = "2020-01-01")
ggplot(stock_prices2, aes(x = date, y = adjusted, group = symbol)) + 
  geom_line(aes(color = symbol)) + 
  scale_color_manual(values = c("darkred", "steelblue")) +
  labs(y = "Adjusted Stock Price", x = "Date", title = "Daily Stock Prices for Target vs. Walmart")

Q8 Hide the messages, but display the code and its results on the webpage.

Hint: Use message, echo and results in the chunk options. Refer to the RMarkdown Reference Guide.

Q9 Display the title and your name correctly at the top of the webpage.

Q10 Use the correct slug.