node.js: process.argv and $ symbol

It's a small issue but nevertheless.. Did anybody picked that node's process.argv removes symbol $ from the string passed to the shell,

example:

mycommand 'mystring: { $exists: true }'

outputs:

[ 'node',
  '/usr/local/bin/mycommand',
  'mystring: { : true }' ]

as you see together with $ disappeared word exists, is it normal behavior?