Spread trading: the construction of a spread

"When you say you are selling the spread, e.g., ZCK23-ZCN23 you are still buying the first symbol and selling the second. I do not see the distinction between buying and selling. If I understand correctly, a buying spread is buying the first symbol and selling the second, where is the difference?"

I take this question to make a clarification about the construction of a spread.

You should not confuse the way a spread is constructed with what you do with that spread. The ZCK23-ZCN23 spread is constructed by buying the corn futures contract with delivery in May (K) and selling the corn futures contract with delivery in July.

Now, what do you do with this spread?

If you have a bullish view, you buy the spread. By buying the spread, the platform (not you) buys the first delivery (May) and sells the second delivery (July). If you have a bearish view, you sell the spread. By selling the spread, the platform (not you) sells the first delivery (May) and buys the second delivery (July).

When you build the spread in the platform, you will have two prices, bid and ask. For example, for the spread ZCK23-ZCN23 the price can be 6.50 (ask) and 7.00 (bid). This means that if you want to buy the spread at market you can do it at €7.00 and if you want to sell it you can do it at €6.50. Put simply, you will buy and sell the price, the platform will take care of the buying and selling of the two futures that make up the spread.

In conclusion, whether you buy it or sell it, the spread is constructed in the same way. What changes is what you decide to do with that spread, buy it or sell it. In the first case, you will be bullish (long) on the first leg and bearish (short) on the second. In the second case, you will be bearish (short) on the first leg and bullish (long) on the second.