library(tidyverse)

Create some data:

smarket_summary <- data.frame(
  year = 2001:2004,
  up = sample(100:200, 4),
  down = sample(100:200, 4)
)
smarket_summary
##   year  up down
## 1 2001 154  109
## 2 2002 121  122
## 3 2003 184  197
## 4 2004 134  188

Reshape the data:

smarket_summary <- smarket_summary %>% 
  gather(direction, value, up, down)
smarket_summary
##   year direction value
## 1 2001        up   154
## 2 2002        up   121
## 3 2003        up   184
## 4 2004        up   134
## 5 2001      down   109
## 6 2002      down   122
## 7 2003      down   197
## 8 2004      down   188

Plot the data:

ggplot(smarket_summary, aes(year, value, fill=direction)) +
  geom_bar(stat="identity", position='dodge')

```