# Load packages
library(tidyverse)
library(tidyquant)
1 Get stock prices and convert to returns
Ra <- c("AMZN", "TSLA", "NFLX") %>%
tq_get(get = "stock.prices",
from = "2022-01-01") %>%
group_by(symbol) %>%
tq_transmute(select = adjusted,
mutate_fun = periodReturn,
period = "monthly",
col_rename = "Ra")
Ra
## # A tibble: 42 × 3
## # Groups: symbol [3]
## symbol date Ra
## <chr> <date> <dbl>
## 1 AMZN 2022-01-31 -0.122
## 2 AMZN 2022-02-28 0.0267
## 3 AMZN 2022-03-31 0.0614
## 4 AMZN 2022-04-29 -0.238
## 5 AMZN 2022-05-31 -0.0328
## 6 AMZN 2022-06-30 -0.116
## 7 AMZN 2022-07-29 0.271
## 8 AMZN 2022-08-31 -0.0606
## 9 AMZN 2022-09-30 -0.109
## 10 AMZN 2022-10-31 -0.0935
## # … with 32 more rows
2 Get baseline and convert to returns
Rb <- "^IXIC" %>%
tq_get(get = "stock.prices",
from = "2022-01-01") %>%
tq_transmute(select = adjusted,
mutate_fun = periodReturn,
period = "monthly",
col_rename = "Rb")
Rb
## # A tibble: 14 × 2
## date Rb
## <date> <dbl>
## 1 2022-01-31 -0.101
## 2 2022-02-28 -0.0343
## 3 2022-03-31 0.0341
## 4 2022-04-29 -0.133
## 5 2022-05-31 -0.0205
## 6 2022-06-30 -0.0871
## 7 2022-07-29 0.123
## 8 2022-08-31 -0.0464
## 9 2022-09-30 -0.105
## 10 2022-10-31 0.0390
## 11 2022-11-30 0.0437
## 12 2022-12-30 -0.0873
## 13 2023-01-31 0.107
## 14 2023-02-08 0.0281
3 Join the two tables
RaRb <- left_join(Ra, Rb, by = c("date" = "date"))
RaRb
## # A tibble: 42 × 4
## # Groups: symbol [3]
## symbol date Ra Rb
## <chr> <date> <dbl> <dbl>
## 1 AMZN 2022-01-31 -0.122 -0.101
## 2 AMZN 2022-02-28 0.0267 -0.0343
## 3 AMZN 2022-03-31 0.0614 0.0341
## 4 AMZN 2022-04-29 -0.238 -0.133
## 5 AMZN 2022-05-31 -0.0328 -0.0205
## 6 AMZN 2022-06-30 -0.116 -0.0871
## 7 AMZN 2022-07-29 0.271 0.123
## 8 AMZN 2022-08-31 -0.0606 -0.0464
## 9 AMZN 2022-09-30 -0.109 -0.105
## 10 AMZN 2022-10-31 -0.0935 0.0390
## # … with 32 more rows
4 Calculate CAPM
RaRb_capm <- RaRb %>%
tq_performance(Ra = Ra,
Rb = Rb,
performance_fun = table.CAPM)
RaRb_capm
## # A tibble: 3 × 13
## # Groups: symbol [3]
## symbol ActiveP…¹ Alpha Annua…² Beta `Beta-` `Beta+` Corre…³ Corre…⁴ Infor…⁵
## <chr> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
## 1 AMZN -0.15 -0.0038 -0.0451 1.46 1.82 3.40 0.857 0.0001 -0.537
## 2 TSLA -0.228 0.0103 0.131 2.10 0.908 3.67 0.765 0.0014 -0.390
## 3 NFLX -0.125 0.0221 0.300 1.96 3.12 2.33 0.788 0.0008 -0.246
## # … with 3 more variables: `R-squared` <dbl>, TrackingError <dbl>,
## # TreynorRatio <dbl>, and abbreviated variable names ¹ActivePremium,
## # ²AnnualizedAlpha, ³Correlation, ⁴`Correlationp-value`, ⁵InformationRatio
Which stock has a positively skewed distribution of returns?
For me AMZN and TSLA are poitivley skewed
RaRb_capm <- RaRb %>%
tq_performance(Ra = Ra,
Rb = NULL,
performance_fun = skewness)
RaRb_capm
## # A tibble: 3 × 2
## # Groups: symbol [3]
## symbol skewness.1
## <chr> <dbl>
## 1 AMZN 0.966
## 2 TSLA 0.656
## 3 NFLX -0.779