# Load packages
library(tidyquant)
library(tidyverse)

# Import stock prices and calculate returns
returns_yearly <- c("^DJI", "^GSPC", "^IXIC") %>%
    tq_get(get  = "stock.prices",
           from = "1990-01-01",
           to   = "2020-11-01") %>%
    group_by(symbol) %>%
    tq_transmute(select     = adjusted,
                 mutate_fun = yearlyReturn)
returns_yearly
## # A tibble: 91 x 3
## # Groups:   symbol [3]
##    symbol date       yearly.returns
##    <chr>  <date>              <dbl>
##  1 ^DJI   1992-12-31         0.0406
##  2 ^DJI   1993-12-31         0.137 
##  3 ^DJI   1994-12-30         0.0214
##  4 ^DJI   1995-12-29         0.335 
##  5 ^DJI   1996-12-31         0.260 
##  6 ^DJI   1997-12-31         0.226 
##  7 ^DJI   1998-12-31         0.161 
##  8 ^DJI   1999-12-31         0.252 
##  9 ^DJI   2000-12-29        -0.0617
## 10 ^DJI   2001-12-31        -0.0710
## # … with 81 more rows

Q1 Create a density plot for the returns of the given stocks.

Hint: Refer to the ggplot2 cheatsheet. Look for geom_density under One Variable. Use the fill argument to create the plot per each stock.

ggplot(returns_yearly, aes(x = yearly.returns, fill = symbol)) +
  geom_density(alpha = 0.3)

Q2 Which stock has higher expected yearly return?

Hint: Discuss your answer in terms of the mean. Take returns_yearly and pipe it to tidyquant::tq_performance. Use the performance_fun argument to compute the mean.

returns_yearly %>%
    tq_performance(
        Ra = yearly.returns, 
        Rb = NULL, 
        performance_fun = mean)
## # A tibble: 3 x 2
## # Groups:   symbol [3]
##   symbol mean.1
##   <chr>   <dbl>
## 1 ^DJI   0.0871
## 2 ^GSPC  0.0880
## 3 ^IXIC  0.143

Q3 Which stock is riskier?

Hint: Discuss your answer in terms of the standard deviation. Take returns_yearly and pipe it to tidyquant::tq_performance. Use the performance_fun argument to compute sd (standard deviation).

returns_yearly %>%
    tq_performance(
        Ra = yearly.returns, 
        Rb = NULL, 
        performance_fun = sd)
## # A tibble: 3 x 2
## # Groups:   symbol [3]
##   symbol  sd.1
##   <chr>  <dbl>
## 1 ^DJI   0.151
## 2 ^GSPC  0.169
## 3 ^IXIC  0.279

Q4 Is the standard deviation enough as a risk measure? Or do you need additional downside risk measurements? Why? Or why not?

Hint: Discuss your answer in terms of the skewness and the kurtosis. Take returns_yearly and pipe it to tidyquant::tq_performance. Use the performance_fun argument to compute the skewness. Do the same for the kurtosis.

returns_yearly %>%
    tq_performance(
        Ra = yearly.returns, 
        Rb = NULL, 
        performance_fun = skewness)
## # A tibble: 3 x 2
## # Groups:   symbol [3]
##   symbol skewness.1
##   <chr>       <dbl>
## 1 ^DJI      -0.669 
## 2 ^GSPC     -0.700 
## 3 ^IXIC      0.0914
returns_yearly %>%
    tq_performance(
        Ra = yearly.returns, 
        Rb = NULL, 
        performance_fun = kurtosis)
## # A tibble: 3 x 2
## # Groups:   symbol [3]
##   symbol kurtosis.1
##   <chr>       <dbl>
## 1 ^DJI        0.410
## 2 ^GSPC       0.357
## 3 ^IXIC       0.289

Q5 Calculate the downside risk measures. Which stock has the greatest downside risk? Discuss HistoricalES(95%), HistoricalVaR(95%), and SemiDeviation.

Hint: Take returns_yearly and pipe it to tidyquant::tq_performance. Use the performance_fun argument to compute table.DownsideRisk.

returns_yearly %>%
    tq_performance(
        Ra = yearly.returns, 
        Rb = NULL, 
        performance_fun = table.DownsideRisk) %>% t()
##                                           [,1]      [,2]      [,3]     
## symbol                                    "^DJI"    "^GSPC"   "^IXIC"  
## DownsideDeviation(0%)                     "0.0743"  "0.0882"  "0.1270" 
## DownsideDeviation(MAR=0.833333333333333%) "0.0775"  "0.0913"  "0.1304" 
## DownsideDeviation(Rf=0%)                  "0.0743"  "0.0882"  "0.1270" 
## GainDeviation                             "0.0935"  "0.1023"  "0.2005" 
## HistoricalES(95%)                         "-0.2530" "-0.3093" "-0.3991"
## HistoricalVaR(95%)                        "-0.1291" "-0.1820" "-0.3541"
## LossDeviation                             "0.1078"  "0.1254"  "0.1605" 
## MaximumDrawdown                           "0.3384"  "0.4012"  "0.6718" 
## ModifiedES(95%)                           "-0.2632" "-0.3017" "-0.4179"
## ModifiedVaR(95%)                          "-0.1831" "-0.2161" "-0.2995"
## SemiDeviation                             "0.1131"  "0.1275"  "0.1931"
returns_yearly %>%
    tq_performance(
        Ra = yearly.returns, 
        Rb = NULL, 
        performance_fun = table.DownsideRisk, p = 0.99) %>% t()
##                                           [,1]      [,2]      [,3]     
## symbol                                    "^DJI"    "^GSPC"   "^IXIC"  
## DownsideDeviation(0%)                     "0.0743"  "0.0882"  "0.1270" 
## DownsideDeviation(MAR=0.833333333333333%) "0.0775"  "0.0913"  "0.1304" 
## DownsideDeviation(Rf=0%)                  "0.0743"  "0.0882"  "0.1270" 
## GainDeviation                             "0.0935"  "0.1023"  "0.2005" 
## HistoricalES(99%)                         "-0.3384" "-0.3849" "-0.4054"
## HistoricalVaR(99%)                        "-0.2906" "-0.3395" "-0.4017"
## LossDeviation                             "0.1078"  "0.1254"  "0.1605" 
## MaximumDrawdown                           "0.3384"  "0.4012"  "0.6718" 
## ModifiedES(99%)                           "-0.4500" "-0.5196" "-0.6014"
## ModifiedVaR(99%)                          "-0.3208" "-0.3679" "-0.4944"
## SemiDeviation                             "0.1131"  "0.1275"  "0.1931"

Q6 Which stock would you choose? Calculate and interpret the Sharpe Ratio.

Hint: Assume that the risk free rate is zero and 95% confidence level. Note that the Sharpe Ratios are calculated using different risk measures: ES, VaR and semideviation. Make your argument based on all three Sharpe Ratios.

returns_yearly %>%
    tq_performance(
        Ra = yearly.returns, 
        Rb = NULL, 
        performance_fun = SharpeRatio)
## # A tibble: 3 x 4
## # Groups:   symbol [3]
##   symbol `ESSharpe(Rf=0%,p=95%… `StdDevSharpe(Rf=0%,p=95… `VaRSharpe(Rf=0%,p=95…
##   <chr>                   <dbl>                     <dbl>                  <dbl>
## 1 ^DJI                    0.331                     0.576                  0.476
## 2 ^GSPC                   0.292                     0.520                  0.407
## 3 ^IXIC                   0.342                     0.512                  0.477

Q7 Redo Q6 at the 99% confidence level instead of the 95% confidence level. Which stock would you choose now? Is your answer different from Q6? Why? Or why not?

Hint: Google tq_performance(). Discuss in terms of ES, VaR and semideviation and their differences between 95% and 99%.

returns_yearly %>%
    tq_performance(
        Ra = yearly.returns, 
        Rb = NULL, 
        performance_fun = SharpeRatio, 
        Rf = 0.01 / 12)
## # A tibble: 3 x 4
## # Groups:   symbol [3]
##   symbol `ESSharpe(Rf=0.1%,p=9… `StdDevSharpe(Rf=0.1%,p=… `VaRSharpe(Rf=0.1%,p=…
##   <chr>                   <dbl>                     <dbl>                  <dbl>
## 1 ^DJI                    0.328                     0.570                  0.471
## 2 ^GSPC                   0.289                     0.515                  0.404
## 3 ^IXIC                   0.340                     0.509                  0.474

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

Hint: Use message, warning, 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.