Get Symbol Double Property¶

Request: retrieve double-type property value for a symbol.

API Information:

Low-level API: MT5Account.symbol_info_double(...) (defined in package/MetaRpcMT5/helpers/mt5_account.py)
gRPC service: mt5_term_api.MarketInfo
Proto definition: SymbolInfoDouble (defined in mt5-term-api-market-info.proto)

RPC¶

Service: mt5_term_api.MarketInfo
Method: SymbolInfoDouble(SymbolInfoDoubleRequest) -> SymbolInfoDoubleReply
Low-level client (generated): MarketInfoStub.SymbolInfoDouble(request, metadata, timeout)

💬 Just the essentials¶

What it is. Retrieve a single double-type property value for a symbol (BID, ASK, VOLUME, etc.).
Why you need it. Get specific numeric symbol properties without fetching all symbol data.
When to use. Use symbol_params_many() for multiple properties. Use this method for single property queries.

🎯 Purpose¶

Use it to query specific double symbol properties:

Get current BID/ASK prices
Check trading volumes
Retrieve margin requirements
Get swap rates
Query tick values and contract sizes
Monitor session prices and limits

📚 Tutorial¶

For a detailed line-by-line explanation with examples, see: -> symbol_info_double - How it works

Method Signature¶

async def symbol_info_double(
    self,
    symbol: str,
    property: market_info_pb2.SymbolInfoDoubleProperty,
    deadline: Optional[datetime] = None,
    cancellation_event: Optional[asyncio.Event] = None,
)

Request message:

message SymbolInfoDoubleRequest {
  string symbol = 1;
  SymbolInfoDoubleProperty type = 2;
}

Reply message:

message SymbolInfoDoubleReply {
  oneof response {
    SymbolInfoDoubleData data = 1;
    Error error = 2;
  }
}

message SymbolInfoDoubleData {
  double value = 1;
}

🔽 Input¶

Parameter	Type	Description
`symbol`	`str` (required)	Symbol name
`property`	`SymbolInfoDoubleProperty` (enum)	Property to retrieve (BID, ASK, etc.)
`deadline`	`datetime` (optional)	Deadline for the gRPC call (UTC datetime)
`cancellation_event`	`asyncio.Event` (optional)	Event to cancel the operation

⬆️ Output - `SymbolInfoDoubleData`¶

Field	Type	Python Type	Description
`value`	`double`	`float`	The value of the requested property

Return value: The method returns SymbolInfoDoubleData object. Access the numeric value via the .value attribute.

Note: In Python code, use the full enum path from the market_info module.

`SymbolInfoDoubleProperty`¶

Defined in mt5-term-api-market-info.proto.

Price Properties¶

Constant	Value	Description
`SYMBOL_BID`	0	Current Bid price
`SYMBOL_BIDHIGH`	1	Maximal Bid for the day
`SYMBOL_BIDLOW`	2	Minimal Bid for the day
`SYMBOL_ASK`	3	Current Ask price
`SYMBOL_ASKHIGH`	4	Maximal Ask for the day
`SYMBOL_ASKLOW`	5	Minimal Ask for the day
`SYMBOL_LAST`	6	Last deal price
`SYMBOL_LASTHIGH`	7	Maximal Last for the day
`SYMBOL_LASTLOW`	8	Minimal Last for the day

Volume Properties¶

Constant	Value	Description
`SYMBOL_VOLUME_REAL`	9	Real volume of the day
`SYMBOL_VOLUMEHIGH_REAL`	10	Maximum real volume of the day
`SYMBOL_VOLUMELOW_REAL`	11	Minimum real volume of the day
`SYMBOL_VOLUME_MIN`	22	Minimal volume for a deal
`SYMBOL_VOLUME_MAX`	23	Maximal volume for a deal
`SYMBOL_VOLUME_STEP`	24	Minimal volume change step
`SYMBOL_VOLUME_LIMIT`	25	Maximum allowed aggregate volume

Trading Properties¶

Constant	Value	Description
`SYMBOL_POINT`	13	Symbol point value
`SYMBOL_TRADE_TICK_VALUE`	14	Calculated tick price for position
`SYMBOL_TRADE_TICK_VALUE_PROFIT`	15	Calculated tick price for profit
`SYMBOL_TRADE_TICK_VALUE_LOSS`	16	Calculated tick price for loss
`SYMBOL_TRADE_TICK_SIZE`	17	Minimal price change
`SYMBOL_TRADE_CONTRACT_SIZE`	18	Trade contract size
`SYMBOL_TRADE_ACCRUED_INTEREST`	19	Accrued interest
`SYMBOL_TRADE_FACE_VALUE`	20	Face value
`SYMBOL_TRADE_LIQUIDITY_RATE`	21	Liquidity rate

Swap Rates¶

Constant	Value	Description
`SYMBOL_SWAP_LONG`	26	Long swap value
`SYMBOL_SWAP_SHORT`	27	Short swap value
`SYMBOL_SWAP_SUNDAY`	28	Swap value for Sunday
`SYMBOL_SWAP_MONDAY`	29	Swap value for Monday
`SYMBOL_SWAP_TUESDAY`	30	Swap value for Tuesday
`SYMBOL_SWAP_WEDNESDAY`	31	Swap value for Wednesday
`SYMBOL_SWAP_THURSDAY`	32	Swap value for Thursday
`SYMBOL_SWAP_FRIDAY`	33	Swap value for Friday
`SYMBOL_SWAP_SATURDAY`	34	Swap value for Saturday

Margin Requirements¶

Constant	Value	Description
`SYMBOL_MARGIN_INITIAL`	35	Initial margin
`SYMBOL_MARGIN_MAINTENANCE`	36	Maintenance margin
`SYMBOL_MARGIN_HEDGED`	48	Hedged margin

Session Properties¶

Constant	Value	Description
`SYMBOL_SESSION_VOLUME`	37	Summary volume of the current session
`SYMBOL_SESSION_TURNOVER`	38	Summary turnover of the current session
`SYMBOL_SESSION_INTEREST`	39	Summary open interest
`SYMBOL_SESSION_BUY_ORDERS_VOLUME`	40	Current volume of buy orders
`SYMBOL_SESSION_SELL_ORDERS_VOLUME`	41	Current volume of sell orders
`SYMBOL_SESSION_OPEN`	42	Open price of the current session
`SYMBOL_SESSION_CLOSE`	43	Close price of the current session
`SYMBOL_SESSION_AW`	44	Average weighted price
`SYMBOL_SESSION_PRICE_SETTLEMENT`	45	Settlement price of the current session
`SYMBOL_SESSION_PRICE_LIMIT_MIN`	46	Minimal price of the current session
`SYMBOL_SESSION_PRICE_LIMIT_MAX`	47	Maximal price of the current session

Price Analytics & Options¶

Constant	Value	Description
`SYMBOL_OPTION_STRIKE`	12	Option strike price
`SYMBOL_PRICE_CHANGE`	49	Change of price in %
`SYMBOL_PRICE_VOLATILITY`	50	Price volatility in %
`SYMBOL_PRICE_THEORETICAL`	51	Theoretical option price
`SYMBOL_PRICE_DELTA`	52	Option/warrant delta
`SYMBOL_PRICE_THETA`	53	Option/warrant theta
`SYMBOL_PRICE_GAMMA`	54	Option/warrant gamma
`SYMBOL_PRICE_VEGA`	55	Option/warrant vega
`SYMBOL_PRICE_RHO`	56	Option/warrant rho
`SYMBOL_PRICE_OMEGA`	57	Option/warrant omega
`SYMBOL_PRICE_SENSITIVITY`	58	Option/warrant sensitivity
`SYMBOL_COUNT`	59	Total count of properties

Usage in Python:

import MetaRpcMT5.mt5_term_api_market_info_pb2 as market_info_pb2

# Access price constants
bid_property = market_info_pb2.SYMBOL_BID  # = 0
ask_property = market_info_pb2.SYMBOL_ASK  # = 3

# Use in method call
bid_data = await account.symbol_info_double("EURUSD", market_info_pb2.SYMBOL_BID)
print(f"BID: {bid_data.value}")

🧩 Notes & Tips¶

Automatic reconnection: Built-in protection against transient gRPC errors with automatic reconnection via execute_with_reconnect.
Default timeout: If deadline is None, the method will wait indefinitely (or until server timeout).
Property availability: Not all properties are available for all symbols. Check broker documentation for symbol-specific properties.
Tick values: Use SYMBOL_TRADE_TICK_VALUE properties for accurate profit/loss calculations.
Volume limits: Always check SYMBOL_VOLUME_MIN, SYMBOL_VOLUME_MAX, and SYMBOL_VOLUME_STEP before placing orders.

🔗 Usage Examples¶

1) Get BID and ASK prices¶

import MetaRpcMT5.mt5_term_api_market_info_pb2 as market_info_pb2

# Get BID price (short format - recommended)
bid_data = await account.symbol_info_double("EURUSD", market_info_pb2.SYMBOL_BID)
print(f"BID: {bid_data.value}")

# Get ASK price
ask_data = await account.symbol_info_double(
    symbol="EURUSD",
    property=market_info_pb2.SYMBOL_ASK
)
print(f"ASK: {ask_data.value}")

# Calculate spread
spread = ask_data.value - bid_data.value
print(f"Spread: {spread:.5f}")

2) Get volume limits for trading¶

async def get_volume_limits(account: MT5Account, symbol: str):
    """Get volume constraints for a symbol"""

    # Get minimum volume
    min_vol_data = await account.symbol_info_double(
        symbol,
        market_info_pb2.SYMBOL_VOLUME_MIN
    )

    # Get maximum volume
    max_vol_data = await account.symbol_info_double(
        symbol,
        market_info_pb2.SYMBOL_VOLUME_MAX
    )

    # Get volume step
    step_data = await account.symbol_info_double(
        symbol,
        market_info_pb2.SYMBOL_VOLUME_STEP
    )

    print(f"Volume limits for {symbol}:")
    print(f"  Min: {min_vol_data.value:.2f} lots")
    print(f"  Max: {max_vol_data.value:.2f} lots")
    print(f"  Step: {step_data.value:.2f} lots")

    return {
        "min": min_vol_data.value,
        "max": max_vol_data.value,
        "step": step_data.value
    }

# Usage:
limits = await get_volume_limits(account, "EURUSD")

3) Get swap rates¶

async def get_swap_info(account: MT5Account, symbol: str):
    """Get long and short swap rates"""

    # Get long swap
    long_swap_data = await account.symbol_info_double(
        symbol,
        market_info_pb2.SYMBOL_SWAP_LONG
    )

    # Get short swap
    short_swap_data = await account.symbol_info_double(
        symbol,
        market_info_pb2.SYMBOL_SWAP_SHORT
    )

    print(f"Swap for {symbol}:")
    print(f"  Long: {long_swap_data.value:.2f}")
    print(f"  Short: {short_swap_data.value:.2f}")

    return {
        "long": long_swap_data.value,
        "short": short_swap_data.value
    }

# Usage:
swaps = await get_swap_info(account, "GBPUSD")

4) Get tick size and contract size¶

async def get_trading_specs(account: MT5Account, symbol: str):
    """Get tick size and contract size for precise calculations"""

    # Get tick size (minimal price change)
    tick_size_data = await account.symbol_info_double(
        symbol,
        market_info_pb2.SYMBOL_TRADE_TICK_SIZE
    )

    # Get contract size
    contract_size_data = await account.symbol_info_double(
        symbol,
        market_info_pb2.SYMBOL_TRADE_CONTRACT_SIZE
    )

    # Get point value
    point_data = await account.symbol_info_double(
        symbol,
        market_info_pb2.SYMBOL_POINT
    )

    print(f"Trading specs for {symbol}:")
    print(f"  Tick size: {tick_size_data.value}")
    print(f"  Contract size: {contract_size_data.value}")
    print(f"  Point value: {point_data.value}")

    return {
        "tick_size": tick_size_data.value,
        "contract_size": contract_size_data.value,
        "point": point_data.value
    }

# Usage:
specs = await get_trading_specs(account, "EURUSD")

5) Check if price is within session limits¶

async def check_price_limits(account: MT5Account, symbol: str, price: float) -> bool:
    """Check if price is within current session limits"""

    # Get session price limits
    min_price_data = await account.symbol_info_double(
        symbol,
        market_info_pb2.SYMBOL_SESSION_PRICE_LIMIT_MIN
    )

    max_price_data = await account.symbol_info_double(
        symbol,
        market_info_pb2.SYMBOL_SESSION_PRICE_LIMIT_MAX
    )

    min_price = min_price_data.value
    max_price = max_price_data.value

    if min_price <= price <= max_price:
        print(f"[OK] Price {price} is within limits [{min_price}, {max_price}]")
        return True
    else:
        print(f"[ERROR] Price {price} is outside limits [{min_price}, {max_price}]")
        return False

# Usage:
is_valid = await check_price_limits(account, "EURUSD", 1.08500)

Common Patterns¶

Validate volume before order¶

async def validate_volume(account: MT5Account, symbol: str, volume: float) -> bool:
    """Validate volume meets symbol requirements"""

    min_data = await account.symbol_info_double(symbol, market_info_pb2.SYMBOL_VOLUME_MIN)
    max_data = await account.symbol_info_double(symbol, market_info_pb2.SYMBOL_VOLUME_MAX)
    step_data = await account.symbol_info_double(symbol, market_info_pb2.SYMBOL_VOLUME_STEP)

    min_vol = min_data.value
    max_vol = max_data.value
    step = step_data.value

    # Check range
    if volume < min_vol or volume > max_vol:
        print(f"[ERROR] Volume {volume} outside range [{min_vol}, {max_vol}]")
        return False

    # Check step
    if (volume - min_vol) % step != 0:
        print(f"[ERROR] Volume {volume} doesn't match step {step}")
        return False

    return True

Get current market price¶

async def get_market_price(account: MT5Account, symbol: str, side: str) -> float:
    """Get current market price for buy or sell"""

    if side.upper() == "BUY":
        # For buy orders, use ASK price
        data = await account.symbol_info_double(symbol, market_info_pb2.SYMBOL_ASK)
    else:
        # For sell orders, use BID price
        data = await account.symbol_info_double(symbol, market_info_pb2.SYMBOL_BID)

    return data.value

📚 See also¶

symbol_info_integer - Get integer properties
symbol_info_string - Get string properties
symbol_params_many - Get all symbol parameters at once