✅ Getting Symbol Double Properties¶

Request: double (numeric) property of a symbol from MT5. Get prices, volumes, swaps, margins, and other numeric symbol parameters.

API Information:

SDK wrapper: MT5Account.SymbolInfoDoubleAsync(...) (from NuGet package MetaRPC.MT5)
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): MarketInfo.SymbolInfoDouble(request, headers, deadline, cancellationToken)
SDK wrapper (your class):

namespace mt5_term_api
{
    public class MT5Account
    {
        public async Task<SymbolInfoDoubleData> SymbolInfoDoubleAsync(
            string symbolName,
            SymbolInfoDoubleProperty propertyType,
            DateTime? deadline = null,
            CancellationToken cancellationToken = default);
    }
}

Request message:

SymbolInfoDoubleRequest { symbol: string, type: SymbolInfoDoubleProperty }

Reply message:

SymbolInfoDoubleReply { data: SymbolInfoDoubleData } or { error: Error }

🔽 Input¶

Parameter	Type	Required	Description
`symbolName`	`string`	✅	Symbol name (e.g., `"EURUSD"`)
`propertyType`	`SymbolInfoDoubleProperty`	✅	Property to retrieve (see enum below)
`deadline`	`DateTime?`	❌	Absolute per‑call UTC deadline → converted to timeout
`cancellationToken`	`CancellationToken`	❌	Cooperative cancel for the call/retry loop

⬆️ Output — `SymbolInfoDoubleData`¶

Field	Type	Description
`Value`	`double`	The requested property value

`SymbolInfoDoubleProperty` - Grouped by Category¶

Current Prices (Bid/Ask)¶

Enum Value	Value	Description
`SYMBOL_BID`	0	Bid - best sell offer
`SYMBOL_BIDHIGH`	1	Maximal Bid of the day
`SYMBOL_BIDLOW`	2	Minimal Bid of the day
`SYMBOL_ASK`	3	Ask - best buy offer
`SYMBOL_ASKHIGH`	4	Maximal Ask of the day
`SYMBOL_ASKLOW`	5	Minimal Ask of the day

Last Price & Volume¶

Enum Value	Value	Description
`SYMBOL_LAST`	6	Price of the last deal
`SYMBOL_LASTHIGH`	7	Maximal Last of the day
`SYMBOL_LASTLOW`	8	Minimal Last of the day
`SYMBOL_VOLUME_REAL`	9	Volume of the last deal
`SYMBOL_VOLUMEHIGH_REAL`	10	Maximum Volume of the day
`SYMBOL_VOLUMELOW_REAL`	11	Minimum Volume of the day

Trading Parameters¶

Enum Value	Value	Description
`SYMBOL_POINT`	13	Symbol point value (minimum price change)
`SYMBOL_TRADE_TICK_SIZE`	17	Minimal price change (tick size)
`SYMBOL_TRADE_CONTRACT_SIZE`	18	Trade contract size (lot size in base currency units)
`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 for deal execution
`SYMBOL_VOLUME_LIMIT`	25	Maximum allowed aggregate volume in one direction

Tick Values¶

Enum Value	Value	Description
`SYMBOL_TRADE_TICK_VALUE`	14	Value of SYMBOL_TRADE_TICK_VALUE_PROFIT
`SYMBOL_TRADE_TICK_VALUE_PROFIT`	15	Calculated tick price for a profitable position
`SYMBOL_TRADE_TICK_VALUE_LOSS`	16	Calculated tick price for a losing position

Swap Values¶

Enum Value	Value	Description
`SYMBOL_SWAP_LONG`	26	Long swap value
`SYMBOL_SWAP_SHORT`	27	Short swap value
`SYMBOL_SWAP_SUNDAY`	28	Swap ratio for positions rolled over from Sunday (0, 1, or 3)
`SYMBOL_SWAP_MONDAY`	29	Swap ratio for Monday → Tuesday
`SYMBOL_SWAP_TUESDAY`	30	Swap ratio for Tuesday → Wednesday
`SYMBOL_SWAP_WEDNESDAY`	31	Swap ratio for Wednesday → Thursday
`SYMBOL_SWAP_THURSDAY`	32	Swap ratio for Thursday → Friday
`SYMBOL_SWAP_FRIDAY`	33	Swap ratio for Friday → Saturday
`SYMBOL_SWAP_SATURDAY`	34	Swap ratio for Saturday → Sunday

Margin Requirements¶

Enum Value	Value	Description
`SYMBOL_MARGIN_INITIAL`	35	Initial margin for opening a position with 1 lot
`SYMBOL_MARGIN_MAINTENANCE`	36	Maintenance margin for keeping position open
`SYMBOL_MARGIN_HEDGED`	48	Hedged margin (for opposite positions)

Session Data¶

Enum Value	Value	Description
`SYMBOL_SESSION_VOLUME`	37	Summary volume of current session deals
`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 of current session
`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 Statistics¶

Enum Value	Value	Description
`SYMBOL_PRICE_CHANGE`	49	Change relative to previous day end in %
`SYMBOL_PRICE_VOLATILITY`	50	Price volatility in %

Options/Derivatives¶

Enum Value	Value	Description
`SYMBOL_OPTION_STRIKE`	12	Strike price of an option
`SYMBOL_PRICE_THEORETICAL`	51	Theoretical option price
`SYMBOL_PRICE_DELTA`	52	Option delta (price change per 1 unit of underlying)
`SYMBOL_PRICE_THETA`	53	Option theta (time decay per day)
`SYMBOL_PRICE_GAMMA`	54	Option gamma (delta change rate)
`SYMBOL_PRICE_VEGA`	55	Option vega (price change per 1% volatility)
`SYMBOL_PRICE_RHO`	56	Option rho (price change per 1% interest rate)
`SYMBOL_PRICE_OMEGA`	57	Option omega (elasticity)
`SYMBOL_PRICE_SENSITIVITY`	58	Option sensitivity

Bonds/Special¶

Enum Value	Value	Description
`SYMBOL_TRADE_ACCRUED_INTEREST`	19	Accrued interest (bonds)
`SYMBOL_TRADE_FACE_VALUE`	20	Face value (bonds)
`SYMBOL_TRADE_LIQUIDITY_RATE`	21	Liquidity rate (asset share for margin)

Internal¶

Enum Value	Value	Description
`SYMBOL_COUNT`	59	The count of symbol properties

MQL5 Reference: SymbolInfoDouble

💬 Just the essentials¶

What it is. Single RPC returning one numeric property of a symbol.
Why you need it. Get current prices, calculate position sizes, check trading constraints, retrieve margin requirements.
Most common. SYMBOL_BID, SYMBOL_ASK, SYMBOL_POINT, SYMBOL_VOLUME_MIN/MAX/STEP, SYMBOL_TRADE_CONTRACT_SIZE.
60 properties covering prices, volumes, swaps, margins, sessions, options.

🎯 Purpose¶

Use this method when you need to:

Get current Bid/Ask prices (alternative to SymbolInfoTickAsync).
Calculate position sizes based on volume constraints.
Retrieve tick value for profit calculations.
Check swap values before holding overnight positions.
Get margin requirements for risk management.
Obtain contract size for lot-to-units conversion.

🧩 Notes & Tips¶

SYMBOL_BID/ASK - use SymbolInfoTickAsync() for faster Bid/Ask retrieval.
SYMBOL_POINT - minimum price change (e.g., 0.00001 for EURUSD).
SYMBOL_VOLUME_MIN/MAX/STEP - critical for validating lot sizes before trading.
SYMBOL_TRADE_CONTRACT_SIZE - lot size in base currency units (e.g., 100,000 for Forex standard lot).
Swap values - charged for positions held overnight (positive = you earn, negative = you pay).
Margin requirements - used for calculating required margin before opening positions.
Properties are cached - use short timeout (3-5s).
Some properties may return 0 if not applicable (e.g., options Greeks for Forex).

🔗 Usage Examples¶

1) Get Bid/Ask prices¶

// Get current Bid and Ask
var bid = await acc.SymbolInfoDoubleAsync(
    "EURUSD",
    SymbolInfoDoubleProperty.SYMBOL_BID,
    deadline: DateTime.UtcNow.AddSeconds(3));
var ask = await acc.SymbolInfoDoubleAsync(
    "EURUSD",
    SymbolInfoDoubleProperty.SYMBOL_ASK);

Console.WriteLine($"EURUSD Bid: {bid.Value:F5}, Ask: {ask.Value:F5}");

2) Get volume constraints¶

// Retrieve trading volume limits
var volumeMin = await acc.SymbolInfoDoubleAsync(
    "GBPUSD",
    SymbolInfoDoubleProperty.SYMBOL_VOLUME_MIN);
var volumeMax = await acc.SymbolInfoDoubleAsync(
    "GBPUSD",
    SymbolInfoDoubleProperty.SYMBOL_VOLUME_MAX);
var volumeStep = await acc.SymbolInfoDoubleAsync(
    "GBPUSD",
    SymbolInfoDoubleProperty.SYMBOL_VOLUME_STEP);

Console.WriteLine($"GBPUSD Volume:");
Console.WriteLine($"  Min:  {volumeMin.Value:F2} lots");
Console.WriteLine($"  Max:  {volumeMax.Value:F2} lots");
Console.WriteLine($"  Step: {volumeStep.Value:F2} lots");

3) Calculate position size¶

// Get parameters for position size calculation
var symbol = "EURUSD";

var point = await acc.SymbolInfoDoubleAsync(symbol, SymbolInfoDoubleProperty.SYMBOL_POINT);
var contractSize = await acc.SymbolInfoDoubleAsync(symbol, SymbolInfoDoubleProperty.SYMBOL_TRADE_CONTRACT_SIZE);
var volumeMin = await acc.SymbolInfoDoubleAsync(symbol, SymbolInfoDoubleProperty.SYMBOL_VOLUME_MIN);

Console.WriteLine($"{symbol} Trading Parameters:");
Console.WriteLine($"  Point:         {point.Value}");
Console.WriteLine($"  Contract Size: {contractSize.Value:F0}");
Console.WriteLine($"  Min Volume:    {volumeMin.Value:F2}");

4) Check swap costs¶

// Get swap values for overnight positions
var swapLong = await acc.SymbolInfoDoubleAsync(
    "EURUSD",
    SymbolInfoDoubleProperty.SYMBOL_SWAP_LONG);
var swapShort = await acc.SymbolInfoDoubleAsync(
    "EURUSD",
    SymbolInfoDoubleProperty.SYMBOL_SWAP_SHORT);

Console.WriteLine($"EURUSD Swap:");
Console.WriteLine($"  Long:  {swapLong.Value:F2}");
Console.WriteLine($"  Short: {swapShort.Value:F2}");

if (swapLong.Value < 0)
    Console.WriteLine("  ⚠️ Long positions pay swap");
else
    Console.WriteLine("  ✅ Long positions earn swap");

5) Get margin requirements¶

// Check margin needed for 1 lot
var marginInit = await acc.SymbolInfoDoubleAsync(
    "XAUUSD",
    SymbolInfoDoubleProperty.SYMBOL_MARGIN_INITIAL);

Console.WriteLine($"XAUUSD Initial Margin: {marginInit.Value:F2}");
Console.WriteLine($"(Required margin for opening 1 lot)");