You can do it with AndroidViewClient/culebra.

Here is an example you can base your script on (autogenerated by culebra):

#! /usr/bin/env python
# -*- coding: utf-8 -*-
"""
Copyright (C) 2013-2018  Diego Torres Milano
Created on 2018-08-09 by Culebra v15.4.0
                      __    __    __    __
                     /  \  /  \  /  \  /  \ 
____________________/  __\/  __\/  __\/  __\_____________________________
___________________/  /__/  /__/  /__/  /________________________________
                   | / \   / \   / \   / \   \___
                   |/   \_/   \_/   \_/   \    o \ 
                                           \_____/--<
@author: Diego Torres Milano
@author: Jennifer E. Swofford (ascii art snake)
"""


import re
import sys
import os


import unittest

from com.dtmilano.android.viewclient import ViewClient, CulebraTestCase

TAG = 'CULEBRA'


class CulebraTests(CulebraTestCase):

    @classmethod
    def setUpClass(cls):
        cls.kwargs1 = {'ignoreversioncheck': False, 'verbose': False, 'ignoresecuredevice': False}
        cls.kwargs2 = {'forceviewserveruse': False, 'useuiautomatorhelper': False, 'ignoreuiautomatorkilled': True, 'autodump': False, 'debug': {}, 'startviewserver': True, 'compresseddump': True}
        cls.options = {'start-activity': None, 'concertina': False, 'device-art': None, 'use-jar': False, 'multi-device': False, 'unit-test-class': True, 'save-screenshot': None, 'use-dictionary': False, 'glare': False, 'dictionary-keys-from': 'id', 'scale': 0.5, 'find-views-with-content-description': True, 'window': -1, 'orientation-locked': None, 'concertina-config': None, 'save-view-screenshots': None, 'find-views-by-id': True, 'log-actions': False, 'use-regexps': False, 'null-back-end': False, 'auto-regexps': None, 'do-not-verify-screen-dump': True, 'verbose-comments': False, 'gui': True, 'find-views-with-text': True, 'prepend-to-sys-path': False, 'install-apk': None, 'drop-shadow': False, 'output': 'aonoff.py', 'unit-test-method': None, 'interactive': False}
        cls.sleep = 5

    def setUp(self):
        super(CulebraTests, self).setUp()

    def tearDown(self):
        super(CulebraTests, self).tearDown()

    def preconditions(self):
        if not super(CulebraTests, self).preconditions():
            return False
        return True

    def testSomething(self):
        if not self.preconditions():
            self.fail('Preconditions failed')

        _s = CulebraTests.sleep
        _v = CulebraTests.verbose

        self.vc.dump(window=-1)
        self.vc.uiDevice.openQuickSettings()
        self.vc.sleep(_s)
        self.vc.dump(window=-1)
        self.vc.findViewWithContentDescriptionOrRaise(u'''Airplane mode''').touch()
        self.vc.sleep(_s)
        self.vc.dump(window=-1)
        self.device.press('KEYCODE_BACK')
        self.device.press('KEYCODE_BACK')

        print >> sys.stderr, 'Now Airplane mode is ON, switching it back to OFF'
        self.vc.sleep(5)

        self.vc.uiDevice.openQuickSettings()
        self.vc.sleep(_s)
        self.vc.dump(window=-1)
        self.vc.findViewWithContentDescriptionOrRaise(u'''Airplane mode''').touch()
        self.vc.sleep(_s)
        self.vc.dump(window=-1)
        self.device.press('KEYCODE_BACK')
        self.device.press('KEYCODE_BACK')


if __name__ == '__main__':
    CulebraTests.main()

You can try AndroidViewClient/culebra which provides also a UI (see Culebra GUI) which allows you to do what you describe as your needs.

Android studios emulator is pretty good nowadays, but very likely the best you could do is use Python to trigger touch events. You won't likely be able to interface directly with the app to do things like trades. Android is pretty good at not letting apps inject touch events and could cause security exceptions. Something as small as rext input would very likely entirely break any attempt to try to do an Android only solution. That being said, if the app exposes intents to do things like trading you could very easily use adb or an app to trigger them, but it seems unlikely that a stock trade app would expose those intents.

Not sure about appium, but AndroidViewClient/culebra can easily do what you want.

Install it, run culebra with or without GUI (-G) and you will be able to automatically generate python tests or plain scripts.

For example, if you run

$ culebra -GuU --scale=0.5 -o chrome.py

while the device is on the home screen and click the Chrome icon to open it, this script will be generated

#! /usr/bin/env python
# -*- coding: utf-8 -*-
"""
Copyright (C) 2013-2018  Diego Torres Milano
Created on 2018-04-04 by Culebra v15.1.2
                      __    __    __    __
                     /  \  /  \  /  \  /  \ 
____________________/  __\/  __\/  __\/  __\_____________________________
___________________/  /__/  /__/  /__/  /________________________________
                   | / \   / \   / \   / \   \___
                   |/   \_/   \_/   \_/   \    o \ 
                                           \_____/--<
@author: Diego Torres Milano
@author: Jennifer E. Swofford (ascii art snake)
"""


import re
import sys
import os


import unittest

from com.dtmilano.android.viewclient import ViewClient, CulebraTestCase

TAG = 'CULEBRA'


class CulebraTests(CulebraTestCase):

    @classmethod
    def setUpClass(cls):
        cls.kwargs1 = {'ignoreversioncheck': False, 'verbose': False, 'ignoresecuredevice': False}
        cls.kwargs2 = {'forceviewserveruse': False, 'useuiautomatorhelper': False, 'ignoreuiautomatorkilled': True, 'autodump': False, 'startviewserver': True, 'compresseddump': True}
        cls.options = {'start-activity': None, 'concertina': False, 'device-art': None, 'use-jar': False, 'multi-device': False, 'unit-test-class': True, 'save-screenshot': None, 'use-dictionary': False, 'glare': False, 'dictionary-keys-from': 'id', 'scale': 0.5, 'find-views-with-content-description': True, 'window': -1, 'orientation-locked': None, 'concertina-config': None, 'save-view-screenshots': None, 'find-views-by-id': True, 'log-actions': False, 'use-regexps': False, 'null-back-end': False, 'auto-regexps': None, 'do-not-verify-screen-dump': True, 'verbose-comments': False, 'gui': True, 'find-views-with-text': True, 'prepend-to-sys-path': False, 'install-apk': None, 'drop-shadow': False, 'output': 'chrome.py', 'unit-test-method': None, 'interactive': False}
        cls.sleep = 5

    def setUp(self):
        super(CulebraTests, self).setUp()

    def tearDown(self):
        super(CulebraTests, self).tearDown()

    def preconditions(self):
        if not super(CulebraTests, self).preconditions():
            return False
        return True

    def testSomething(self):
        if not self.preconditions():
            self.fail('Preconditions failed')

        _s = CulebraTests.sleep
        _v = CulebraTests.verbose

        self.vc.dump(window=-1)
        self.vc.findViewWithContentDescriptionOrRaise(u'''Chrome''').touch()
        self.vc.sleep(_s)
        self.vc.dump(window=-1)


if __name__ == '__main__':
    CulebraTests.main()

then you can run it as

$ ./chrome.py

to achieve the same at any time