Introduction to MetaTrader 5

MT5 is provided through brokers. Sign up with a broker that offers MT5 (most major brokers do). You can also use a demo account to practice without risking real money.

Your broker will provide a download link, or you can download MT5 directly from the MetaQuotes website. MT5 is available for Windows, macOS, Linux (via Wine), iOS, and Android.

Run the installer, then enter your broker account credentials (server, login number, and password). For demo accounts, you can create one directly from the platform.

Go: open a terminal in a folder you can write to — cd ~/Desktop on macOS or Linux, cd %USERPROFILE%\Desktop on Windows.

Do: save this as odp.py and run python3 odp.py.

"""MT5's three-way model. Getting this wrong confuses everything after it."""

# An ORDER is a request. A DEAL is an execution. A POSITION is what you hold.
orders, deals, positions = [], [], {}

def send_order(oid, symbol, side, volume, price):
    orders.append((oid, symbol, side, volume, price, "placed"))
    return oid

def execute(oid, deal_id, fill_price):
    for i, (o, sym, side, vol, price, state) in enumerate(orders):
        if o != oid:
            continue
        orders[i] = (o, sym, side, vol, price, "filled")
        deals.append((deal_id, oid, sym, side, vol, fill_price))
        # Netting: one position per symbol, adjusted by each deal.
        held = positions.get(sym, 0.0)
        positions[sym] = round(held + (vol if side == "BUY" else -vol), 2)
        if positions[sym] == 0.0:
            del positions[sym]

send_order(101, "EURUSD", "BUY", 0.50, 1.1000); execute(101, 9001, 1.1001)
send_order(102, "EURUSD", "BUY", 0.30, 1.1010); execute(102, 9002, 1.1011)
send_order(103, "EURUSD", "SELL", 0.80, 1.1050); execute(103, 9003, 1.1049)
send_order(104, "GBPUSD", "SELL", 0.20, 1.2700)     # placed, never filled

print("ORDERS -- requests you sent")
for o in orders:
    print("   #%-4d %-7s %-4s %.2f @ %.4f   %s" % o)

print()
print("DEALS -- executions that happened")
for d in deals:
    print("   #%-4d from order #%-4d %-7s %-4s %.2f @ %.4f" % d)

print()
print("POSITIONS -- what you currently hold")
if positions:
    for sym, vol in positions.items():
        print("   %-7s %+.2f" % (sym, vol))
else:
    print("   (none)")

print()
print("orders sent    :", len(orders))
print("deals executed :", len(deals))
print("positions held :", len(positions))
print()
print("Three orders became three deals and ZERO positions -- the third deal")
print("closed exactly what the first two opened. The fourth order is still")
print("waiting and is not a position at all.")
print()
print("This is why 'my trade disappeared' and 'I have two positions but one")
print("order' are both normal. In MetaTrader 5 the three are separate things:")
print("   an ORDER is an instruction         (may never be filled)")
print("   a DEAL is one execution            (immutable history)")
print("   a POSITION is your current holding (built from deals)")

You should see: four orders, three deals and no positions:

ORDERS -- requests you sent
   #101  EURUSD  BUY  0.50 @ 1.1000   filled
   #102  EURUSD  BUY  0.30 @ 1.1010   filled
   #103  EURUSD  SELL 0.80 @ 1.1050   filled
   #104  GBPUSD  SELL 0.20 @ 1.2700   placed

DEALS -- executions that happened
   #9001 from order #101  EURUSD  BUY  0.50 @ 1.1001
   #9002 from order #102  EURUSD  BUY  0.30 @ 1.1011
   #9003 from order #103  EURUSD  SELL 0.80 @ 1.1049

POSITIONS -- what you currently hold
   (none)

orders sent    : 4
deals executed : 3
positions held : 0

Three orders became three deals and ZERO positions -- the third deal
closed exactly what the first two opened. The fourth order is still
waiting and is not a position at all.

This is why 'my trade disappeared' and 'I have two positions but one
order' are both normal. In MetaTrader 5 the three are separate things:
   an ORDER is an instruction         (may never be filled)
   a DEAL is one execution            (immutable history)
   a POSITION is your current holding (built from deals)

MetaTrader 5 keeps three separate records and the terminal has a separate tab for each, which is the source of most early confusion:

• An order is an instruction you sent. It may sit unfilled forever, and order #104 above is doing exactly that.
• A deal is one execution that really happened. Deals are history and never change.
• A position is what you currently hold, assembled from deals.

So “my trade vanished” is usually correct and not a fault. Three deals produced zero positions here because the third closed what the first two opened — the deals remain in the history tab forever, and the position tab is empty because you hold nothing.

This also explains a common surprise for anyone arriving from MetaTrader 4, where an order was the position. In MT5 they are different records with different identifiers, which is why an EA that closes “order 101” will not find it.

If not: python3: command not found on Windows means Python was installed without “Add python.exe to PATH”; try py odp.py. If a position remains, the volumes no longer cancel — 0.50 plus 0.30 against 0.80 is what empties it.

Go: the same folder.

Do: save this as netting.py and run python3 netting.py.

"""Netting or hedging: the account setting that changes what your EA does."""

def apply(deals, mode):
    if mode == "netting":
        net = 0.0
        for side, vol in deals:
            net += vol if side == "BUY" else -vol
        return [("EURUSD", round(net, 2))] if round(net, 2) != 0 else []
    positions = []
    for side, vol in deals:
        if mode == "hedging":
            positions.append(("EURUSD " + side, vol))
    return positions

DEALS = [("BUY", 0.50), ("BUY", 0.30), ("SELL", 0.20)]

print("the same three deals, on two kinds of account:")
print()
for mode in ("netting", "hedging"):
    result = apply(DEALS, mode)
    print("%-9s -> %d position(s)" % (mode, len(result)))
    for name, vol in result:
        print("             %-14s %+.2f" % (name, vol))
    print()

print("Netting: one position per symbol. A SELL against an open BUY reduces")
print("it. You cannot be long and short the same instrument at once.")
print()
print("Hedging: every deal opens its own position with its own ticket, stop")
print("and target. You can hold opposing positions simultaneously.")
print()
print("Why this matters to an EA: 'close my position' is one operation on a")
print("netting account and a loop on a hedging one. And a strategy that")
print("opens a second position expecting to scale in will, on a netting")
print("account, silently just enlarge the first one -- with the original")
print("stop-loss still attached to the whole thing.")
print()
print("Check with AccountInfoInteger(ACCOUNT_MARGIN_MODE). Do not assume:")
print("it is set by the broker per account, and the same EA meets both.")

You should see: the same three deals producing one position or three:

the same three deals, on two kinds of account:

netting   -> 1 position(s)
             EURUSD         +0.60

hedging   -> 3 position(s)
             EURUSD BUY     +0.50
             EURUSD BUY     +0.30
             EURUSD SELL    +0.20

Netting: one position per symbol. A SELL against an open BUY reduces
it. You cannot be long and short the same instrument at once.

Hedging: every deal opens its own position with its own ticket, stop
and target. You can hold opposing positions simultaneously.

Why this matters to an EA: 'close my position' is one operation on a
netting account and a loop on a hedging one. And a strategy that
opens a second position expecting to scale in will, on a netting
account, silently just enlarge the first one -- with the original
stop-loss still attached to the whole thing.

Check with AccountInfoInteger(ACCOUNT_MARGIN_MODE). Do not assume:
it is set by the broker per account, and the same EA meets both.

This is a broker setting, not a preference of yours, and the same Expert Advisor will meet both. On a netting account there is at most one position per symbol and an opposing deal reduces it. On a hedging account every deal opens its own position with its own ticket, stop and target, and you can be long and short simultaneously.

The consequence for code is larger than it looks. “Close my position” is a single operation on netting and a loop on hedging. Worse, a strategy that opens a second position to scale in will, on a netting account, simply enlarge the first — with the original stop-loss still attached to the whole, larger, holding.

Ask rather than assume: AccountInfoInteger(ACCOUNT_MARGIN_MODE) tells you which one you are on, and an EA meant to be shared should handle both or refuse to start on the one it does not support.

If not: if both modes report the same count, the mode argument is not reaching the branch — netting sums the deals into one net figure, hedging keeps each as its own entry.

Go: the same folder.

Do: save this as margin.py and run python3 margin.py.

"""Balance, equity, margin, free margin -- and which one closes your trades."""

def account(balance, positions, prices, leverage=30):
    used_margin = 0.0
    floating = 0.0
    for sym, vol, entry, contract in positions:
        notional = vol * contract * prices[sym]
        used_margin += notional / leverage
        floating += (prices[sym] - entry) * vol * contract
    equity = balance + floating
    free = equity - used_margin
    level = (equity / used_margin * 100.0) if used_margin else float("inf")
    return balance, floating, equity, used_margin, free, level

POSITIONS = [("EURUSD", 1.0, 1.1000, 100000)]

print("%-10s %9s %9s %9s %9s %9s %9s" %
      ("PRICE", "BALANCE", "FLOATING", "EQUITY", "MARGIN", "FREE", "LEVEL%"))
print("-" * 74)
for price in (1.1000, 1.0950, 1.0900, 1.0850, 1.0800, 1.0750):
    b, f, e, m, fr, lv = account(10000.0, POSITIONS, {"EURUSD": price})
    flag = ""
    if lv < 50:    flag = "  <- STOP OUT"
    elif lv < 100: flag = "  <- margin call"
    print("%-10.4f %9.2f %9.2f %9.2f %9.2f %9.2f %8.1f%s"
          % (price, b, f, e, m, fr, lv, flag))

print()
print("BALANCE   money from CLOSED trades. It does not move while a trade is open.")
print("EQUITY    balance plus the profit or loss of open trades. This is real.")
print("MARGIN    the deposit the broker holds against your open positions.")
print("FREE      equity minus margin -- what is left to open anything else.")
print("LEVEL     equity / margin. The broker acts on THIS number.")
print()
_, _, e0, m0, _, lv0 = account(10000.0, POSITIONS, {"EURUSD": 1.1000})
_, _, e1, m1, _, lv1 = account(10000.0, POSITIONS, {"EURUSD": 1.0750})
print("Balance never changed in that table. Equity fell by %.0f and the"
      % (e0 - e1))
print("margin level went from %.1f%% to %.1f%%." % (lv0, lv1))
print()
print("Traders watch balance because it is the big number at the top. The")
print("broker watches the margin level, and when it falls far enough your")
print("positions are closed for you at whatever price is available -- not at")
print("your stop, and not at a moment of your choosing.")

You should see: balance frozen while equity falls by 2,500:

PRICE        BALANCE  FLOATING    EQUITY    MARGIN      FREE    LEVEL%
--------------------------------------------------------------------------
1.1000      10000.00      0.00  10000.00   3666.67   6333.33    272.7
1.0950      10000.00   -500.00   9500.00   3650.00   5850.00    260.3
1.0900      10000.00  -1000.00   9000.00   3633.33   5366.67    247.7
1.0850      10000.00  -1500.00   8500.00   3616.67   4883.33    235.0
1.0800      10000.00  -2000.00   8000.00   3600.00   4400.00    222.2
1.0750      10000.00  -2500.00   7500.00   3583.33   3916.67    209.3

BALANCE   money from CLOSED trades. It does not move while a trade is open.
EQUITY    balance plus the profit or loss of open trades. This is real.
MARGIN    the deposit the broker holds against your open positions.
FREE      equity minus margin -- what is left to open anything else.
LEVEL     equity / margin. The broker acts on THIS number.

Balance never changed in that table. Equity fell by 2500 and the
margin level went from 272.7% to 209.3%.

Traders watch balance because it is the big number at the top. The
broker watches the margin level, and when it falls far enough your
positions are closed for you at whatever price is available -- not at
your stop, and not at a moment of your choosing.

Balance is the money from closed trades, so it does not move at all while a position is open. That is why it is reassuring and why it is the wrong number to watch: in the table above it reads 10,000.00 throughout while the account is losing 2,500.

Equity is what you actually have, and the margin level — equity divided by the margin the broker is holding — is the number the broker acts on. When it falls far enough, positions are closed for you, at whatever price the market offers, not at your stop and not at a moment you chose.

Two practical consequences. First, the account panel's most prominent figure is the least informative one; add equity and margin level to what you watch. Second, an EA that sizes positions from AccountInfoDouble(ACCOUNT_BALANCE) will keep sizing as though nothing has happened while the account is deep in a drawdown — size from ACCOUNT_EQUITY instead, and the position size shrinks automatically as things go badly, which is the behaviour you want.

If not: if the margin level does not fall, the floating profit is not being added to equity — equity is balance plus the open profit or loss, and it is the falling equity rather than the slightly falling margin that moves the ratio.